Welcome aboard!
I would buy the speakers you have chosen and run them with your Yamaha, it has more than enough power to drive the M80s and VP180 to very loud levels, maybe not for long periods but it will work without the added expense of the separate amps. Once you know whether or not the Yamaha works the way you desire, you can then decide on that amp purchase for which the XPA 3 has more than enough power to drive the front 3, that extra couple hundred watts available in the XPA2 amounts to about 1-2 db higher output, not really noticeable at those high output levels.
