Right off the bat, you don't want to mix and match brands with your front three speakers.
Second, I probably wouldn't bother with floorstanding speakers; instead I'd put the money towards a better subwoofer.
Third, while I won't knock Polk and Klipsch (I own and am satisfied with Klipsch speakers), I'd definitely shop around a bit/do more research/listen to as many brands as I reasonably could before plopping down your cash. Some people find a lot of value in internet direct brands for instance (Ascend, Aperion, et al), and you might find you prefer speakers from other brands such as Infinity, JBL, Energy, Paradigm, PSB, etc...