I worked at a major car sound retailer for 3 years and we did a couple of 'lines, including mine. From memory they were series 1's. Front and rear are definitely 6.5"s, I have 6" polks in the front and have had to make up MDF spacers to make them fit.
Although the front speakers are your main stage, I think you should run rear speakers as fill only as they can really beef up your mid base. By that I mean fade them all the way out and then bring them back in until you can just hear the mids fattening up. Well that's my opinion anyway
My 2c's:D