I used a fish tank at the start with my bp. The main differences are the thickness of the glass and the lid need locks. I hated those clip on locks. In the end, it did not matter what I want, because my bp did not eat for weeks until I moved him to a 6qt tub. It may not be appealing at first (I really did not like tubs prior to the switch) but it is a whole lot easier to maintain humidity and can help a baby bp settle in easier. Fyi, snakes can escape from tubs too so you will need to be diligent about keeping the lids secure by using the store purchased locks (for glass tanks) or binder clips (for tubs).
If you choose to go with glass tanks, my suggestion is to use a Critter Cage or a terrarium that comes with a sliding door and they are lockable so you will get that peace of mind.
Pick up some fake plant decor pieces from your local dollar store or hobby stores. Something bushy to clutter up your tank. Also, blacking out the sides and back of tank helps.
If you want to save money, I would switch to tubs from the start and wait until after it is full grown to pick up an enclosure or go back to glass tanks.
Lastly, read all the stickies on what to do with your new snake including how to properly thaw out the prey.