I'm looking for a 1/4 in. truss rod wrench for a BC tich guitar

Edgar,
How are you determining that the neck is not straight? If you are thinking the neck is not straight because the strings are at different heights along the neck, the problem may be neck tilt or saddle and/or bridge height. You can raise or lower the bridge system or string saddles to add or subtract string height along the neck. In addition, neck tilt (particularly easy to adjust on bolt-on necks) refers to the angle that the guitar neck exits the neck pocket on the guitar body. This also effects string height.
Conversly, if you see a distict bow or bend in the neck when you look down the top edge of the neck, the truss rod may indeed be involved. Generally, most players like a little bit of "relief" in the neck. That is to say, a little bit of a concave bow. I prefer a relatively straight neck with very little relief. Just preference.
However, you mentioned you already adjusted the truss rod. Make sure the truss rod is functional. If you loosen the bolt or hex on the truss rod and the concave bow on the neck gets more pronounced, it is likely that you truss rod is ok. If you make adjustments on the bolt and there is little or no change on the neck relief, it is possible that your truss rod is not functioning or is broken. It is very possible to break a truss rod by over tightening but it would take some real effort to do. Still, it is possible.
Check out those points and see if it helps.
Confirm truss rod is working.
Check bridge height and saddle height.
See if adjusting neck tilt is possible on your model guitar.
Good luck.

Take the truss rod cover off. Take the one of the screws and carefully run some super glue into the screw thread (not directly in the hole). Put it in the problem hole and screw in, leaving a bit of the screw sticking out. Leave it over night to set. Remove the screw with a screwdriver, replace the cover and replace all screws. This technique works well for many screws, although the bigger one, such as strap buttons work better with a good quality wood glue.

Takes a standard 'Allen Key' hexagonal wrench (I'm not sure of the size for your specific guitar but most are around 5 or 6mm)
Basic Epiphone manual here
http://www.epiphone.com/images/EpiOwnrsManul.pdf

To fix the action on your B.C.Rich Warlock, you need an Allen Wrench, or Hex key. There is a truss rod cover on your B.C.Rich's headstock. Just open it using a screwdriver and you will find the truss rod. Then adjust the action using the hex key.
check out more here -
http://www.squidoo.com/b-c-rich-warlock-set-up-and-fixing

Have you changed strings on it? Old strings get worn spots in them from rubbing on the frets that will cause these type of symptoms. If you put new strings on and get the same issue, check your neck relief (the amount of bow in the neck) to do this, hold your low E string at the first fret, and at the 12th or 14th fret. The neck should have a slight bow in the middle that puts it between 1/16" and 1/8" or so away from your string. If it does not have enough bow in it, you can adjust the truss rod. Most guitars use an allen wrench for this, it will be inside the soundhole on an acoustic usually, and on an electric it is normally on the headstock under a cover. There are many how-to's online about adjusting a truss rod, the key is to do it very slowly, only do about a 1/2 turn a day, retune, check it again the next day. Loosen the truss rod to put more neck relief, tighten to straighten the neck. If this still doesn't fix you up, let me know, and I'll tell you where to go from there.

The truss rod must be too slack then.
Is the sound ok? Does it play ok?
In it's current state the truss rod is doing nothing.
If the guitar is sounding ok and playing ok, then the next time you change the strings pull the truss rod out and throw it in the garbage.lol
Seriously though...just pull it out and put it aside.
If,however,the guitar is not sounding ok then try tightening it.
If you're unsure about how much to tighten it then I suggest taking it to your local music store for help with that.

No the truss rod is usually in more than that. Take it to a reliable Musice Store and they shold be able to adjust it for you.

Dont give up on the neck. One tec you saw may not know what another that has had many years in the repair of gtrs knows !. But for the time being you can fix this your self. Find a alan wrench that came with your Gtr.thats your ntail pice. This is the bridge that each string cross,s over. Now slowly rase up the height of the string untill its high enough to stop the buzzing. Just half turns at a time. . All so if you keep the humitdy up near your gtr. it may correct its self, no **** just like magic. keep on playing DFD

I can understand it a bit of a daunting task setting up these guitars (I have bought at least 5 like this) But yes it might be the truss rod ... Without looking at the guitar myself its hard to say ... If you tighten the truss rod remember how much you turned the allen wrench because if it doesnt work your going to need to reset it and start again ... Remember to turn it the right way! and if all else fails ... If your near me (Bournemouth, South of the UK) then you can always pop on over to mine and I can take a look at it.

Failing that just take it to your nearest guitar repair shop and a setup should cost you about £30 if your in the UK.

Actually you can do this by adding shims under the saddle to raise the action. Then use the truss rod to make the action uniform if necessary. I try to avoid making adjustments to the neck because it could lead to undesirable perminent alteration to the neck. If you do make adjustments to the truss rod you should tune the guitar to pitch and let it sit left alone overnight to allow the wood time to adjust to the new adjustments.

Here is a link to an article on Adjusting action on an Acoustic Guitar.