Thanks guys for all the feedback.
Gprent my initial plan was actually to buy an air pump with correct cylinder size etc from Thickwall but the cost is the same as for the Bathmate and Bathmate and the advantages of water pumping kept coming up In my research which is what made me so confused. If you use an air pump with water don’t you take gauge off anyway from what I’ve read elsewhere on this site? Which makes me think I should just go for the Bathmate and SomethingToBe’s gains are impressive.
Still thinking about it but whatever I decide I’ll record my progress on here.