I've owned the ThunderFunk 750, the Puma 1000, and a Genz Benz Shuttle 6.0. In the cabs I've owned the DB112's. So my recommendation? None of these!! Check out the TC RH450 with a pair of Berg HT/EX112ER's. Best damn bass rig I have ever heard!! Don't let the 450 watts scare you, it will keep or do better than any of the rigs you are looking at.
This doesn't quite pass the sniff test to me. I'm sure that rig sounds great, but my experience with the Berg Mini stack is that, while it's a great sounding little punchy rig, no matter what head was used, it would not keep up volume-wise with any of the options above, including two DB112's (although that one would be at least close, although the DB112's have much better low end extension than the original HT/EX stack to my ear). I agree though that 450 watts would be plenty to drive those small cabs to full volume.