The Pioneer is near the top of their regular lineup before you step up to the elites. My experience is that they tend to be great receivers but their room calibration is much different that the very lauded Audyssey calibration. Pioneer claims their calibration is much better for EQ on a multichannel system (as it is a graphical EQ system vs. the Parametric of the Audyssey), but I can't really speak to this having never compared them side by side although the pioneer setup.
One other point, Pioneer remotes are the biggest POS's ever created by man. The have many buttons doing double duty with a function key etc, and the manual and setup of the receiver are much more complicated than is needed. I always hated explaining how to use Pioneers to people.
Anyway, you're not going to hate yourself for getting the Pioneer, but there are most likely better options. Just my opinion on the Pioneer if nothing better presents itself.
Anyway, the down stepping line conditioner would be a great idea (as it would give you many more option on components), but its going to significantly raise the price point of the system and you may not need it in the future.
I take it you are stationed somewhere without many options. Are you going to keep the receiver when your deployment ends?