Thanks everybody for all the suggestions so far. I have limited internet access as we have shut down the house as we leave in the morning for our summer trip! I am not quite sure where to start. Book a one way soon or wait for availability to do return flights to book a round trip with stopovers and then add flights to complete the trip?I have burned a lot of United miles for the trip I an now commencing and don't think I can replenish enough to do this with star alliance .I won't be able to acquire miles until we get back in September.