Both are good starter snakes. The only conscern about the redtail would be size. I have two redtails, a hypo and a normal columbian. The columbian was my first snake, i bought him as a hacthling. I have never had him strike at me or anything, and hes fairly easy to take care of if you have the room. Also there are smaller versions of redtails if you are willing to spend the money. Hogg Island Boa is the first to come to mind, think they top out around 5'-6(similiar to a BP in size). What it came down to for me was i liked the look of redtails more then BP's. HOpe the helps!
The hypo Harli
The columbian Willie
Sorry about the big pics! Matt