Lots. You could go with a cheap Shady Boy for around $100 if I remember right, though I don't recommend it.
Next up are the $2-300 ARB/Smittybilt/CVT/Rhino Rack standard type awnings that can be found on Ebay, Amazon or at any offroad place. The best, in my opinion, is the CVT (Cascadia Vehicle Tents) which you can get directly from them.
Next jump in price is probably the $700 Batwing type awning, made by Rhino Rack. Look it up, it's pretty neat.
The factory Sportsmobile (and other small RV converter) type is a Fiamma, which is all cool and Euro and expensive at around $900-1200.
On top of the price of the awning you'll need some gutter brackets which 1der (forum username) can hook you up with. Sportsmobile also has them, or you could mount to a roof rack if you have a fixed top or no top. Gutter mount style brackets are the easiest way to mount an awning on a pop-top van. Expect about $200 more for them.