rear discs
 

is it possible to convert the rear drums on a 1994 323 hatchback to disc brakes? would maybe suspension from a miata fit or something?

Yeah you can do the swap.... its actually very simple if you have all the parts. You'll want a rear disc suspension off a 90-94 Protege LX: rotors, calipers, mounts, etc. Don't forget the parking brake cable assy. I have not done the install yet on my 323 but I know a few guys who have and its basically a bolt-on deal. No fabrication or major headaches involved.

Isn't there a master cylinder or something like that that has to be added?

Yeah you could swap out the brake master cylinder off your 323 with one off a Protege LX but I think they are pretty much identical and the swap is not necessary.

How come you want to go to rear discs? The drums have better stopping power, but the disc's cooling is a lot better. So it depends on if you're running track, street, or, just going for looks ;) .

the majority of braking occurs up front (unless you pull the handbrake) anyways... changing to drums isn't going to affect too much as long as your front disks are up to parr.

You'll want to get the proprotioning (my spelling sucks) valve from the LX and swap those out too, your master cylinder will be fine to use.