I use the ernie ball super slinkys... for some reason I just don't agree with a heavy gauge string.. odd because I try to play SRV'ish and he plays (played) tuned down 1/2 a step with extra heavy strings....

the thing is to find what feels good when you bend, strum, whatever... took me a while to realize that to emulate I don't have to completely imitate them... also, the guitar may not be setup for different gauge strings. check the book that came with it or ask the guitar dude in your local music store..

when I first tried the heavy gauge strings on my strat..let me just tell you, it went over like a fart in church!