Emotiva XPA-2 & XPA-3 or just XPA-5

[Tanooki]

So I'll be buying my speakers in a few weeks (Axiom M80's/QS8's/VP160) and was wondering if it would be better to just a get a simple XPA-5 and have them all nicely powered.

Or would it be better to get an XPA-3 now (I don't have budget to get both at same time) to power the front 3 speakers and use the receiver to power the last 2 for now. Then later get the XPA-2 use that to fully power the M80's and use the XPA-3 to power the QS8s and the VP160?

Thanks