I would recommend getting two banties.
In my standard hens, the banty girls were always at the bottom of the pecking order, but as a duo they held their own. They kind of looked out for one another. Then one went broody on me and that ended their little friendship. Later, we kept one of the broody banty's hatchlings and now the two of them are sticking together (the baby is now 8mos old). When the baby was big enough, I put her and Momma in together with everyone and it took the baby about month before the bigger girls would leave her alone, but Momma hen always tried to stand up for her.
Oh yes, and over the fall I got a 4th banty - this time a silkie... and she is sweet and tame. Oddly enough nobody messes with her. Maybe the fur like feathers freak them out? It's kind of sad though - while they don't mess with her, she seems like the loner of the group. I'm thinking about getting her a silkie buddy this spring. We'll see.
Wow... sorry for the long drawn out note. I'm not sufficiently caffeinated yet this morning.