whats the smallest plane i could get to carry at least 7 oz of weight?

Well, this depends a little on pilot skill. Any 40 size trainer could easily carry an additional 7oz (less than half a pound). I am guessing you are looking into onboard camera equipment here. With a little more effort a 25 size trainer could haul the load as well.

great, yeah thanks for the help. i am looking into a camera system and im still trying to find out all the details for what plane to get. this is a big help though thanks
-PN