Agree--they'll find you. Bagan vs Yangon: how much overall time do you have for this trip? Two full days in the Nyaung-U/Bagan area is usually OK, a third day to do a road trip to Salay and Mt. Popa. Yangon probably has enough for a couple of days. In Burma, on any travel day between cities, it's best to treat the balance of that day as bonus time, to allow for logistical irregularities. You can comfortably do Yangon + Bagan (assuming air travel between the two) in 5-6 days. If you have additional time...1 day, 2 days, 7 days...I'm sure we have plenty of other suggestions. I've yet to meet a person who went to Burma and cut out early voluntarily--most people lament they didn't have more time to spend.