i know that PDM has some camber kits.... will they work on any height 240sx? also what other kits r there?
and cost if u have some

How much have you lowered your car?

You can get 1 bushing kit from PDM and it will give you +/-.75 degrees of camber adjustment. If you get two bushing kits it will give you +/-1.5 degrees.

I don't think there really is anything else to fix the camber for the rears. Ingalls makes a bolt kit for the front. Otherwise Cusco makes some rear tie end rods that will allow for adjustment and of course you can always get Pillow Mounts, but even still some rear pillow mounts wont allow for camber adjustment.

i don;t know how low yet
looking at 1.75... will that be too low with a body kit?

1.75 is about as low as you will want to go. I lowered mine 1.3 front and 1.1 rear with my 5Zigen's and I had to take off my stock s13 front lip because it drug everywhere. It depends on your body kit a little too. What springs are you going to use?