I'm thinking the 250 would match up with the HCCA subs. Not sure how big they are, but I don't think they'd need a 275. You can find lots of HCCA 250's on ebay. The better ones, G4's and GS's are a lot harder to find, but there's always a Digital Reference on ebay.
Its a dual 2 ohm sub...rated 600rms...i've desided to stay away from 2 channel amps and bridging them...this sub wants power so it'll just overheat a bridged amp in little to no time...i'm going to run it at 4 ohms as i'd rather not just an amp at 1 ohm...more of a personal preferance thing...
Also had a potential at getting a JL 500/1 for 300 shipped used for about 1 week with original paperwork and box...