Should work. I don't understand why you can't find a cheap one at the same place you get the bottle though. If I knew more about these things I could help you better, but this one looks like it has the right connection. Find out what the thread size is on the output, what the hose barb size is, what the output pressure is, etc.. Or at least find out if you can send it back if it won't work for any reason. It looks to me like you could take off the output hose barb, use a brass threaded nipple to connect the flowmeter directly to the regulator, then use that same barb, if it's the right size, on the out connection to the flowmeter. The barb looks pretty big to me, though.