Suggestions for Class A/B Bass head with big power @ 4 ohms

I'm shopping for a bass head to power a fEARful 1515/66 cab that will handle 1500 watts. At this point, there is the Aguilar DB 751 and the Genz Benz GBE 1200. Besides these two giants, what other bass heads give big power at 4 ohms ? I'm committed to this fearful but I'm shopping for the head. I'd rather use a head instead of separates (I know that separates will offer far more options for power). For example, which of the two heads above has more balls for clean low end ? Some of you may have experience with both of the above heads. I'll use this rig for Reggae. (I'm already using 1500 watts which gives me wonderful headroom.) And, it's true that this fEARful does not have to have huge power to sound awesome - but I really like clean headroom on stage.