Plan on getting 6x9 and 5.25 door speakers was looking at these for 6x9s

Amazon.com: polk audio 6x9

and these for door speakers

Amazon.com: Polk Audio DB521 5.25-Inch Coaxial Speakers (Pair, Silver): Car Electronics

Never used Polk audio just trying to get some input and what small amp would you run wiith those not trying to spend a whole lot