Depends on how fussy you are about your audio.
If you go to the effort of purchasing high-end speakers (in this case Polk Audio), then go to the effort of doing a great audio install also.
Sound proof the doors with FatMat, inner and outer, use an amplifier power wiring kit... and seeing OP wants to run amp(s) for his speakers, go with a 4 gauge power kit. Use some OFC speaker wiring and you're pretty much set.
Later on then you have room to expand with... capacitor, power splitter, amplifier for sub, sub woofer(s), etc.
No use putting $300 speakers in the doors with a powerful amp behind them and no sound proofing... they will probably sound rather bad (hollow/tinny), and rattle like hell.
Do a proper install the first time, you won't be disappointed later.