I don't know of any seedbox providers based out of Bangladesh, as most of the seedbox providers are concentrated in Europe (Amsterdam, Germany, France particularly).
You can think of Seedbox.io / Seedhost / Ultraseedbox / Feralhosting, all of them are very reputable providers and offer very good value for money.
You can also directly get in touch with D_Bug (https://www.crazyhd.com/index.php?page=userdetails&id=416268
), he has some nice dedicated seedboxes for a decent price.
All the Best! If you have any queries, feel free to revert here or PM me.