I don't like the way the screw clamps chew up the hose. The tools for the flat clamps like yours and the round wire Corbin clamps are readily available. Try the better auto parts stores for the pricier made in USA versions and the discount stores or Amazon or eBay for the cheaper copies made in you know where. The further away they are made the cheaper they are.

Or you could use Gates Power Grip clamps. They are heat shrink rings that you put on with a heat gun. Very smooth,. Nothing sticking out to cause blood leaks But they are a single use clamp. You have to cut them off. Not really suitible for on and off type applications.