i would go back to the beginning of cow-punk, and check out the catalog of Jason and the Nashville Scorchers. not necessarily Rock-a-billy, but definitely a train-wreck of punk and roots. not sure if you guys are looking for covers, or original material, but the vibe of these guys is rippin and your punk rock buddy will approve. Hank III would be a good place to look as well. I'm jealous! i wish you guys luck. 20 years ago had a band that was in this vein, i miss it alot! i played pretty clean tone (still do, lol), just a little OD, and mixed in a little slap-back or trem when called for.