I'm thinking of getting one so I can develop my own b&w film, check which negs I like then ask for those ones to be printed. I'd be able to use bulk film then to. I know nothing about them (this is my first post in this forum I think), so is there anything special I should consider before buying or they much of a muchness? I'd like the develop 135 and 120 film. Should I get a tank which does both or two tanks? I think I read a while ago that Patterson are good. Oh, and what's your view on a second hand one?