That amp is crap. Pretty much all those amps on that site are. some decent ones, but not many.The rf is ok, still mid level. and still not enough power for 2 w6's
Did you check out the aq or RD?
and i would put at least 750-1000 on them. They will be fine if its set up right. ie, not clipping.
check out the AQ 1200 or the aq2200 both solid amps.
the rd has a 1750 i believe that would do well too.
Both of those are in that price range.
There are many other great amps out there too. But in general, if they have a spider/skull/ flames on em kep away. The same can be said for amps with chrome or other flashy shiney lights and junk.