i have a pair of 4" 4021i

Top Mount Depth: 1-7/8 Inches
Sensitivity: 91 dB
RMS Power Range : 2-35 Watts
Peak Power Handling: 105 Watts
Impedance: 4 Ohm
Frequency response: 85-21000 Hz
Design: 2 Way
Woofer Composition: Plus One+ poly
Tweeter Composition: Edge-driven silk
Diameter: 4 Inch

and pair od 6"x9" 9622i

Top Mount Depth: 3-1/16 Inches
Sensitivity: 94.7 dB
RMS Power Range : 2-100 Watts
Peak Power Handling: 300 Watts
Impedance: 2 Ohm
Frequency response: 46-21000 Hz
Design: 2 Way
Woofer Composition: IMPP
Tweeter Composition: Textile
Diameter: 6x9 Inch

was wondering do i need a 4 channel amp?
I dont have subs i just want some quality sound, what specs of amps should i be looking at, thanks guys

An Amplifier will always give you better sound and control then the ones they put in headunits. A good 50 watt per channel should do the trick, just set the crossover around 100 hz. Depending on your listening habits you may beable to sceek it down abit more. On the 6/9's you could set the crossover around 60 hz or so.