You might check your local fireplace stores, especially if they carry specialized grils, smokers, etc. That's where I find stuff like that. The one I go to has every wood you can imagine to cook/smoke with. I cook with red oak chunks as well, but I just cut my own as I happen to have tons of them around the house.
one of my favorites is pork loin filetd out about 2inches thick , then make a walnut and apple stuffing . roll that up so it looks like a pin wheel . then based it with a can of coke , but the best part is it is being smoked on a piece of hickory or oak . momma will be happy and so will your belly . and fish smoked on poplar wood is very good . and a steak on a piece of apple or cherry is awsome.and any bamby steaks is a true treet.