Ok the 50x4 amp in that unit is not going to cut the mustard if you want to get over the top of your vehicles noise floor ( the sum of all the noises created by the car eg, wind, road, tyre, exhaust, engine etc). Firstly what is your budget? secondly don't bother with rears unless you plan on using them for low frequencies (below 250Hz).
If you want to get away with minimal cost but end up with a reasonably good quality system I'd suggest
1) A good 2 way component set of speakers
2) A 4 Channel class D amp (4 x 150watt) 2 x 150watts for fronts & 1 x 300watt for sub.
3) A subwoofer
Contrary to your request I've suggested a sub because you won't get the lower frequencies & thump without spending a considerable amount of money on the front speakers and installation.
So your budget will come into play as to what you will be able to get, if you want good quality and don't mind getting S/H gear shop at the for sale section at MEA but don't forget to make an allowance for installation:
http://www.mobileelectronics.com.au/forums...hp?showforum=41