these Polk speakers any good?

I have dealt with that website before and they were very good IMO. If you don't plan on adding a sub I would suggest a good set of 6x9's in the front (a 6x9 has more cone area than a 6.5 so the 6x9 would actually produce more bass with all else being equal). It's a matter of opinion whether 6.5's sound better than 6x9's however I would bet that if you did a side by side of the same model speakers in 6x9 vs 6.5 you'd be hard pressed to say the 6.5 sounded better with all else being equal.
Rear speakers are a personal preference so you'd have to decide on that one. If you are looking for a "competition type" soundstage I would say not to use them as it will be more difficult to implement them properly. If you like music all around you or just a little fill then use rears if you want! In any case if I was on a specific budget I would spend the dough on a good set of front speakers installed properly rather than a set of mediocre fronts and mediocre rears (you could always add the rears later when budget permits if desired).

 

yeah thanks for the advice...hey i pm'd you about possibly getting the mounting brackets...you make those right? oh and one more suggestion...since i'm not going with componet speakers...is there any advantage going with 3 or 4 way vs. 2 way?

 

Yes I do make the adapters and I will answer your PM shortly. Also, 3 or 4 way speakers are a "gimmick" and I personally would stick with a 2 way or a 6x9 component set.