suggestions on 6in coaxial speakers?

So I am brand new to this stuff and recenly a friend of mine gave me 2x 12in subwoofers ad a bose amp.

I am hoping someone can give me a good recommmendationon 4 coaxial 6in speakers that I can us to replace the stock speakers in my for mecury sable? I would like to keep the 4 speakers under 200$ as a whole and i would be installing it myself.

thanks.