Yep, Air Bagan. They have F100s, ATRs and an A310.
Your cell phone won't work in Myanmar, no credit cards or ATMs and internet is restricted.
Good hotels in Yangon are Traders, which is slap back in the centre of downtown, SummitParkview, which has a "nightclub" BNE, next door and is opposite one of the largest pagodas in town, Shwe Dagon, or if you want more space Espace Avenir, which is owned by HtooTrading who also own Air Bagan.
You could try booking
here, the girl in the picture is one of their cabin crew, Saw.
BTW, You will need to have your visa sorted prior to arrival otherwise they won't let you leave BKK.