Just my quick thoughts. For country music, have you tried iTunes? At least there you could listen to them before downloading/paying for them. Now, for your choice of dances, does your studio offer Country Two Step? I think that the Two Step, East Coast Swing, and some waltz would cover most of the country dances. For other modern "party" dances, then Cha Cha, Merengue, and Bachatta would be good choices.