BG250-208 user here. I don't play a 5 string so won't say for certain that it can handle it on it's own however I know when I pair it with a RS112 cabinet, it will have zero problem handling a low B. What I like about the BG250-208 is that it is the BH250 head, crammed into a 2x8" cab with the choice of using the 2x8" speakers plus an extension cab (via speakon connector) or disconnecting the 2x8" speakers from the head and using two 8 ohm cabs of your choice. It gives you some room to grow as you do. May be a bit more than you are looking to spend when you factor in the cabs but it's a very versatile combo unit.