need help deciding on my audio build

Mr Pinchy

Sorry Nismo13807 didn't mean to imply you were being cheap. Just didn't make sense that you are using high end speakers with an entry level amplifier. That being said here are three amps ,of many, I have used or are currently using and I am very pleased with them all. They are all four channel and can be purchased from $325 to $450 at this time.

JL XD400/4VS
Currently using to power components in the front and one ten inch sub.

Memphis 15-MCX4.75

Arc Audio FD4150

I like to experiment with various brands. These will provide exceptional sound at high levels with no distortion.

Also you mentioned you do not want a sub. The speakers behind the seats add almost no sonic impact or overall quality to the sound of the system. My feeling is a sub would contribute much more to the sound of your system. Zenclosures makes an awsome enclosure custom built to fit our cars. They will even adjust the cabinet airspace to your sub's requirement. I have this with a 10 inch sub and it sounds incredible. You could also purchase a sub enclosure and attach it to rear deck but I really like the finished look of the Zenclosure. Any of the amps listed above are bridgeable meaning you can combine one rear left and one rear right channel as one to drive one woofer at 200 to 250 RMS. When and if you decide to add a sub. Hope this helps.