That hifonics 1606 might actually give you a couple hundred more watts of power. If the kicker is rated at 1000w x1 @1ohm, and the Hifonics 1606 is rated at 1500w x1 @1ohm (prolly gonna put out like 1350-1400w, but ive actually heard the new hifonics stuff puts out what its rated for a change.) then youre going to get more power off the hifonics.
The new hifonics stuff isnt supposed to be too bad, i dont mind the sound of hifonics amps but ive only heard the old line, the new line is better.
I'd go with whatever is cheapest if youre low on cash. I'm not a big fan of kicker amps put i trust the company and theyre def gonna put out what theyre rated at and do a good job doing it.