Need help with my hose

Try a non-lever Stant from NAPA. I'm not sure what the best pressure level is for your car/engine.

Not sure what you mean by an 'overflow can'; is this a plastic bottle with a tube running into it from just below the radiator cap? If so, this is a reservior for excess coolant that pushes out when the cap reaches its pressure limit. The 'vacuum valve' under the cap is what would allow the the excess coolant to be drawn back in as the coolant in the system cools down.

Without the coolant can and recovery, you probably can't run without an air pocket in the radiator; if the system gets hot enough, then expanding coolant will be lost and you will always end up with the air pocket. It all depends on if your car is always cool enough as to whether this works OK; I'd sure try to find a place for a can (if you don't indeed have one). With a coolant can, the air pocket should evetualy work out; you just add coolant to the can as it drops.