The ESP Guitar Company

Sperzel, Planet Waves and Grover have a few options that would work.

between schaller and sperzel, my vote easily goes to the schaller based on a few reasons.. i find the thumb screw much more comfortable with the schallers. the tuning ratio is higher for more accurate tuning. in your case it will require no modifications to the guitar.. and finally i find it easier to fit bigger gauge strings..

I was thinking about getting one of these and upgrading all the hardware too. How about the bridge and tailpiece, is that an easy replacement as far as matching the existing drilled holes for the stock bridge?

You can always do Sperzels without drilling. Just pull the set pin out and tighten them with the nuts on the tuning head. I've done that a couple of times and never had an issue. I think the EC-256 would look cool if you got the chrome Sperzels with the faux ivory tuning keys. It would go with the vintage look.

ok, tnx for clearing :)

seems logical enough ;)

I see this is an old thread but I've got the same question as the OP, except that I already own one. Mine is a cherry/black burst with chrome accessories. #1 concern is that I'm hoping to find locking tuners that will just drop in. The Schaller are on my short list. I'm also planning on replacing all/some/most of the chrome with black chrome, largely depending on what I can find. 

Any help would be appreciated. 

BTW I bought the guitar with no set-up beyond the factory. I'm quite picky about set-up and I was pleasantly surprised to discover it arrived with no set-up needed. It plays great and any mods I'm planning aren't to correct any deficiencies.