Good advice, thanks mate.

I guess what I'm wondering is, what can I get away with, can you get 2 feet of growth in an 8 inch pot without to much cramping? 

Then if you did do that...would it be ok the following season, would the roots just stop growing and it would get used to a smaller pot? 

Just don't have the room for a hundred cactus in full size containers along with tomatoe and pepper plants!

Thanks again for the responses,

D