I have a stock coupe without Bose. I put in new JVC speakers in back, 6x9. They sound pretty good. I want to upgrade the fronts, which are 5 1/4. Will any other speaker size fit in there without modification?

I have the stock head unit still. I really want one that has an iPod input but I still wanna use my steering wheel controls. Can this be done or should I just get a transmitter?

Any suggestions on speakers and transmitters?
I'm on a budget also

Thanks guys!