I feed mine small/medium also, about 1/2 to 3/4" at most.

You could also consider mail order crickets. Joshsfrogs sells them and you can choose the size.

I buy about 200 at a time and buy them small so they are still okay if they grow a little. I have a 10 gallon tank setup for them. Works just fine. I use eggcrate flats in an upright position to keep them from crawling all over each other and it allows their feces to fall to the bottom.