fs frame?
 

if i were to buy a fs frame could i use some of my hard tail components on it or would they not be compatible?

Yes. Depending on the frame EVERYTHING should be. Some systems will not be but for the most part you should be fine.

The only thing that could vary would be the bottom bracket, fork steerer tube, and chain length.

*knobbymojo sends a subliminal message "get a giant"*;)