I own two EPX3000s which I use for top cabinets. letitrip is right, they are not great subwoofer amps; but those subs need a fairly high HPF and do not need a ton of power, so the EPX3000 is probably okay for them. You certainly will want an outboard crossover / DSP to protect your subs from damage and be able to adjust the crossover point to the tops.
The EP2500/EP4000 is my current subwoofer amp of choice. I would like to have better ones but these are $325ea vs $2000+ for a real upgrade, so I'm not going to upgrade them anytime soon.