Onlinecarstereo.com has great prices and buy some 5.25" adapter plates. I replaced my 4x6" plate Polk db's with 5.25" clarion 3 ways and it sud 10x's better. If you are running off the headunit's power I would buy a speaker 35 wrms or less.
FYI, To install the 5.25" speaker in the factory 4x6 spot does require you to cut a metal support bracket off the dash. It is best to use a dremel with a cut off wheel
1997 Wrangler 4.0 Sport, 4" RC x flex lift, 33" boggers 5-speed, hard top, full doors, Cuurie front bumper, superwinch 9.5ti, Hella e-code w/ ddm tuning HID 5K kit
1989 Cherokee 4.0 4" lift w/ 31" tires (sold)