Yes, 500VA should be plenty per side! They say that 500VA is where the kit starts to need a soft-start circuit though, so if you're willing to reduce VA a little you might be able to omit the soft-start. If you're putting both sides on the same breaker, then you'd be over 500VA in any case so then it's a moot point. (And it's only a detail anyway ...)
I haven't auditioned the Amp1/5/10 series, but the distortion specs for the chipsets in Amp4/11 and Amp7/15/Truepath are significantly better, and from what I gather from reviews the sound quality seems higher too ... However, I have seen people rave about their Amp10s, even in comparison with the other ones, so it seems you can't go wrong with 41Hz

... that's been my experience at least.
The maximum voltage for the Amp1/5/10 series is in part mandated by the TA2022 chip. (Probably also the on-board caps and stuff.) The datasheet (for example here
here) says +/- 36V, which indicates a transformer of about 24V.
I'm not sure I follow that the bridged Amp7 would need a separate PS. I must say I'm not experienced with bridged amps, but can you share the reasoning behind the separate PS requirement?
Hope this helps!