you do NOT want oats PWO. They are too slow digesting, which also affects the digestion of protein. You want fast digesting (high GI) carbs, such as that of malto/dex. Before i got malto/dex i just drank some grape juice along with my protein. Just buy some malto/dex from www.bulknutrition.com, i think it will be under $15.

Also, save the tuna for your PPWO.