I used to use a Profile AP600 to run a set of Polk component speakers and I can't say I had any complaints about it. Seemed to provide a decent amount of clean power. I used it for a year and a half. I now have it in a friends truck and it's still working as intended.
For running an active setup I'd look into a headunit that has active crossovers. You'll be able to set crossover frequencies much more accurately that way and you'd have multiple slopes to use as well.
Saw that you have a 4ch cadence amp listed in the classifieds. If it would help you at all, I have an old alpine 3672 4 way active crossover that I could sell to you for not very much. Maybe you could still use your cadence amplifier this way and not have to worry about what crossover adjustments are available on it. PM me if that would work for you, otherwise the amplifier from ebay sounds like a good deal to me.