Boyfriend coming to visit.

Okay, so I live in Zhuhai, Guangdong. I am here under a work permit. I have an ex-fiance in the states and we have recently reconciled and want to give things another try. Basically, we want him to come and live with me while we work things out and if they do, then in a years time fly back to the states and get married and he returns on a spouse visa. We also plan to travel and do plenty of tourist-y things while he is here. I am not sure whether we should apply for the L type one or the short-term visit type? Whichever one will allow him to stay for the longest amount of time is preferable.