It's been my experience that amps with a DF of 200 or more sound the best. If the PE amps are only 30 or 40, that's horrible! I've heard amps that had a DF of between 100-200 that didn't sound good to me.

The Mackie 1400i looks pretty decent. There's a couple of them on ebay for a not too bad price. I'd have to run it in stereo as it makes way too much power for one Tempest in bridged mono (well in excess of 1000 watts). It puts out 250 X 2 in stereo into 8 ohms. I think its DF is over 300. I will also look at some of the others you mentioned and see what's out there.