Any other rich-flavoured, white dry bean would do as well. I'm in zone 5a or 5b, ample growing season. I grew a few types of dry bush beans this year and even got a second crop off some of them. Next year I want to do only pole beans. I would prefer an open-pollinated variety. I have found white runner beans, but I don't think they have the flavour I'm thinking of.
No. Marrow beans, as well as most shell/dry beans, were developed for field cultivation, and bush types were (and still are) more efficient. I can think of one variety that may interest you, and that is the 'White Emergo' runner bean, Which can be used as a dry bean, with qualities described as similar to cannellini. This pole veriety can climb up to 8-10 feet. It can be harvested green, or left to dry. If that isn't what your after, you may be out of options.