In 2019 we used Columbus Travels for full itineraries including flights, hotels, local drivers/guides, etc. It worked well for this trip and some other trips that other family members have done pre-2020. It came recommended by overseas Burmese-Americans. Here is their contact information.

Branch Office (Inbound Tour Department)
No.290, Room No. 10, 04th Floor, Pyay Road, Corner of ZawTiKa Street.
San Chaung Township, Yangon.
Phone : +951 503830, 523536, 2305838
Fax : +951 2305868
Email : [email protected]
Web : www.travelmyanmar.com

Head Office
586 Strand Road, Corner of 07th Street, Lanmadaw Township Yangon.
Phone : + 951 229245 (Hunt Line) / 227845
Fax : +951 222790
Email :[email protected]
Web : www.travelmyanmar.com

I don't know what things are like post-Covid/coup but perhaps this could be helpful to you.