The Level Three will give you more bass, and you can get by
with-out a sub. The Level Two towers will have decent bass
and can sound nice with Classic Rock >> however, they may
not have enough bass for you.
While I would prefer the HTD Level Two towers, over the Primus
speakers >> The Infinity 363/362 towers may be better for you,
if overall bass is most important.
Funny you mention the P363 as that is one of the ones I have been looking at. That is an unbelievable price , unfortunetley we don't have a Fry's near us in upstate NY. The level 3's are very nice speakers but a little more than I want to spend.