I've been thinking about it and here are my thoughts.
The 470's have combined bass and midrange driver. The 570's have dedicated drivers for bass and midrange. I was thinking there won't be much of a difference when the bass is taken over by the sub. Is this correct or will the 570's just sound better, period.
As for the amp I don't think I can afford anything else now
my budget is stretched tight (its actually way over). But my plan is to add a Rotel RB-1070 (120 x 2) for the front channels later using the pre outs.