Wiring question

You could bridge your amp to get more power to one set of speakers, then just run the other set off your head unit. Just make sure when you bridge the amp your speakers can handle the RMS max.

First off your cerwin vegas are fine, secondly I would just use the 4 channel amp, and not wire any speakers to the head unit. The head unit you bought is probably somewhere around 23 watts rms per channel, and the 4 channel you have is 35 watts rms, so go with the four channel. As for bridging the amp like KAILUAZ suggested, I wouldnt. From my experience, when you run one set of speakers from the head unit, and one set from a seperate amp, you tend to get a little echo effect because not all the speakers are going off at the right time. It could be a matter of less than a 1/2 a second, but you will notice it and you will probably not like it. So either way you go, I would avoid bridging the amp, just my opinion.