can a guy use propane alone in this stove , or do you have to have a mix as the specs suggest
Well all the compatible fuel canisters you can buy are this same mix, and I've never heard of an adapter to pure propane, so it shouldn't be an issue.
The bigger issue is whether or not the canister will fit. A canister with a lindal valve should work, regardless of the exact mix. Generally speaking, though, the popular brands (MSR, etc.) are going to have blends that give you the best general performance, especially as the temperature drops.