I've got a siphon feed unit from Sears and it works great. I've done the entire body, fenders, hood, frame, etc and never had any warpage.
I use "blackblast" which is a black sand type material packaged in Minnesota and sold here in Wisconsin by Menards (a store just like Home Depot).
I wear a hood, glasses and breathing mask. Dirty work, yes, but then it's fun because it's all part of the building process.