Todd, I agree with Craig and Rick; your 352 is plenty. Rather than being overkill so much, the 150 watt amp would be surprisingly little extra kill. The difference between 80 and 150 watts is only 2.73dB in additional peak sound output(e.g. 112.73dB compared to 110dB on a peak of split second duration), which it's likely that you'd never get any benefit from. The connection between the two amps would simply be two cables with RCA connectors on each end from the pre-outs of the 352 to the inputs of power amp, but don't waste your money; spend it on something that would make a real difference.
Incidentally, no, bridging has nothing to do with what you were considering. Some two-channel amps(including some NADs)have a provision for connecting both amp channels to one speaker in a special way(bridging)which results in twice the voltage driving the speaker. Since Ohm's Law states that power is proportional to voltage squared, doubling the voltage would theoretically increase the power four times(rather than just doubling it). In practice, losses result in roughly a tripling of the power. So now you know that, but don't worry about it.
