I bought a Rush Pro for the green Twenty and it used Kool Stop Continentals up front and thinline Kool Stops in the rear with the stock brake.

My Phillips uses a Rush BMX brake up front with Kool Stop cartridge pads in an Avid holder.. this brake is not as stiff as the Pro model but still works rather well.

If you find some long reach Raleigh steel brakes these work really well as they are very solid and have very little flex.

You should really look at replacing the front wheel as then you may find that Kool Stops with the stock brakes makes a good combo... the rear brake will always be anemic unless you fit a drop bolt and use a much better brake.