First of all, DON'T ride in March-April!! The whole region will be super hot and you are sure to regret coming at this time. Better to arrange things to come during the winter months, Nov.-Feb. or simply go elsewhere.
I found cycling in Bangladesh to be good with friendly people and interesting historic and religious sites. It's also intriguing because so few tourists come here. The foolish visa prices further reduce the number of visitors. You could probably get a Myanmar visa easily in Dhaka; but verify first!
I am thinking of cycling from India to Thailand via Myanmar in December of this year.
Yes, the www.puncturesandpanniers.com website is a great source of information for India to Thailand.
Another source, though Thailand to India, is www.crazyguyonabike.com/doc/14930 and a search on the Internet will turn up others.
