For a loud rock band I wouldn't choose anything less than a 410 or 212. The 410 could be 2x210's and the 212 could be 2 112's. If a 212 is too wide maybe the new Barefaced 310 would work for you.
I gig in a stupidly loud blues rock band and use 2 Barefaced 112's and a 700 watt amp, and am never drowned out by anyone. I'd also suggest a trolley, but I hardly use mine since buying the BB2 and SM 112's. Even with a bad back, they are light enough to carry during 99% of load ins.