On my former 2008 and on the current 2013 Allegro Buses I use a bra from Coastline RV and Offroad
Coastline RV and Off Road - RV Products
They stock a number of bra's and if they don't have yours, they'll custom make one for you in about a day if you make an appointment and bring them the coach. They're in Rancho Cucamonga, CA (near Ontario airport).
Beside the two bra's I have bought for the coaches, I've also bought two for two pickup toads. I couldn't be more pleased, and if I have to replace the coach or the toad, I'd definitely buy another.