Polks are an awesome choice for speakers. I have them in mine and couldnt be happier. Paired with a nice set of tweeters and it sounds amazing.
99 Grand Cherokee Limited 4.0
PERF:Custom Built CAI, Straight Side Exits Exhaust No Mufflers/ Flowmaster slip on tail / cat delete (Interchangeable)
EXT:Tinted Tails, 10000k HID Lows, 20% Window tint all around,
INT:Custom Blue LED lighting
AUDIO:Kenwood headunit, Polk and Infinity door speakers, Diamond 1200.1 amp 2 kicker L7 12's in a ported box