It probably isn't worth getting it fixed cause it'll either cost more than it's worth or just blow out again shortly after. Save up and buy a decent branded amp IMO. while Hifonics are good to start out, they're really nothing compared to the higher quality amps.
The IA's are fantastic amps. I'd put them above HiFonics, but that might just be me. I'd recommend them. Go for it!
I'm not saying that HiFonics aren't good, they are great amps to start off with or for just a small little system. But after a while most people want bigger and better. I was actually about to buy a hifonics bx1606 but then changed my mind cause I changed my system plans to need higher power.