Bear with me for a minute...
NAD manufactures an integrated amp (370) and a stand alone power amp (270) which is simply the power amp section of the 370. In this case, it would be perfect for bi-amping.
Now, I'm not intimately familiar with the Musical Fidelity line, but if they manufacture a separate power amplifier that exactly matches the A3.2's power amp, you should be fine. All the gain and power math will have been done for you.
In any case, being all four channels would be identical, you would probably be better off using both channels of one amp for each side. i.e. bass and mid/highs from one chassis.
Bass can draw a lot of power and having one amp providing the bass for both channels could strain the amp. Having only one channel per chassis handling the bass will afford a little more headroom overall.
Mind you, unless that power amp is an exact match for your integrated's power amp, like the NAD example, all bets are off