What works for me, but in a non racing context, is alloy brake plates, long rear brake arms, brake shoes with the hollow filled in and about one and two thirds linings on each shoe, twin cables which I made myself from very robust industrial cables, a 'wiffle tree' on the handlebar brake lever to even up the pull on the wo cables and no balance beam. Instead two very robust attachment on the front of the girdrauic brakes to take the lower end of each cable. With this set up there is no sponge in the system. Instead the handle bar lever just comes to a stop. On one occasion in a panic stop when a lady pulled straight across the front of me I had the rear end in the air at about 30 mph. Don't ask me to do it again. I checked the latest club shop price for the alloy brake plates and was surpised to see that they are over £500 each!