What Baer's are you running? If you're running the Track setup with standard PBR 2-pistons up front and single pistons out back a MC with a 15/16" bore size works quite well. The Baer provided MC for this setup is sourced from a '77 Malibu with manual brakes, 15/16" bore size. That's what I'm currently using and am quite happy with the setup in terms of pedal feel and travel. About $50 at your local auto store, NAPA being my preference.
If you want something that looks a little snazzier a Wilwood Tandem in 1" bore size will also work well; pedal effort will be slightly higher (not an issue with the Hydroboost) and pedal stroke will be slightly shorter than the 15/16" MC.
http://www.wilwood.com/Products/006-...TCMC/index.asp