I took in a 10 foot burm not too long ago (recently adopted out). Reason why he was found a home is because I am the only person in the house that enjoys my snakes and will handle them.
This snake was not always a happy snake when being cleaned and fed. Having a 10 foot burm strike at you is not fun. Let alone a 18-20 footer if you get a female.
If you do not have anyone to help you I would advise against a Burm or other giant snake.
Every time I need to deal with my burm I always envisioned myself getting tagged during a SFE (stupid feeding error) and not being able to get him off of me.
I am sticking with my BCI, BCC, and Dums for now (for the big guys).

If you have any questions let us know.