Sorry if this sounds redundant - Offhand, simply wondering about Karate Monkey's 29 wheels & sizing up a suitable frame. Realizing being fitted in a shop for measurements will expedite matters, I'm leery about a couple of the local (nearby) store employees & classifieds owners being a bit too blase' in regards to what they wanna sell me - Thought I'd try here for some suggestions. Basically, height is 5'8, and was sold a 17" Specialized & 18" Giant in the past. Will the 29 wheels be better served by sizing down to a 16"KM, or "medium size"d 18"?? Thanks for being patient w/me!