just about anything from a smallish car will fit with brackets.
 
Ive used some SB Barina seats in my thou 4-door with success. (They are for sale too, but i suspect the postage would kill it)
They sat higher than the originals, but still usable. I could fit in fine, but im only about 175cm tall.
 
I worked out that the max width and length of the seat should be 50x50cm max.
 
If the seat needs to flip forward for access into the rear seat, then that makes it harder.
Perhaps Hyuandai coupe might be a winner.
 
If you want somehing to bolt straight in, then it has to be thou seats from any of the other models.