best amp for ma 15 eho4 subs

I was running a hk4000d on a pair of MA Audio 15" EHO4 subs, but one day I went out to my truck and opened the door and I instantly had the burnt up amp smell in the cab, but the truck was off. The amp still plays but the bottom half of the mosfets are toast. Still can't quite figure that one out. The amp never got hot at all then just one poof. I was wondering if anyone has run any different, more powerful amps on these subs. This is my daily driver but I like my doodie loud. I already have a beefed up alternator, 1/0 wire and Optima battery. I can handle a decent amount of power draw. With the HK up all the way the only time I had alot of power drain is when I was at a stoplight with my cooling fan on (truck radiator) and the heater going. Other than that the alternator kept up with the power needs of that amp.

Come on now, I know someone out there has pushed these subs beofore, I want to know what they will hold as a daily driver and for burps at a competition

I'm sure that amp requires more than a single battery and one run of 0 gauge. What was your voltage with the system at full tilt??