The upper radiator hose is the best place, Your plan sound reasonable. You may have to cut the internal spring (if present) to add the adaptor, or compress it back to clear.
Cut the hose first using a sharp knife and then use wire cutters to cut the spring.I hope that I cut it in the right spot so I get a nice tight fit........ Is it tricky cutting through that radiator spring so you get a nice clean cut?