Yeah I'm gonna agree with Wegs, I've been training 5-6 days a week somehwere between bodybuilding and powerlifting style, pretty much incorporating both, and getting by just fine on 6 hrs of sleep per night, no overtraining. I could probably bump it up to 7 if I wanted, definitely if I was guaranteed 9 hrs of sleep per night.
You kind of gotta work up to the work capacity but it doesn't have to be taht taxing on your CNS. If your'e training westside style or bein one of those ppl who only does singles, doubles, and triples (stupid shit for most people imo) then yeah, you're gonna be hard pressed to train 7 days a week, but if you're training in the 5 rep range which works better for strength gains for most ppl anyways, it shuldn't be too bad on recovery.
I think it's worth trying to incorporate some powerlifting into your routine, workin up to it slow, if nothing else it will help with size gains too.