If you want good brakes, two things are key: chrome rims and correct set-up. Any U brake will work great if you set it up right, and Odyssey Evolvers are by far the easiest to set up. Chrome rims are everywhere, but most Arayas (especially Super 7xs), most Alexes (not Supra E, very heavy) and Odyssey Hazzard Lites are the best.
As for completes, I'd recommend the Micromachine. It has black rims, but these are easily changed. The KHE and Titus have SD rotors, not normal Gyros, and I haven't heard anything good about them. The Chromsome is a good bike for the money, but it's probably quite heavy. If you can afford the FLy and some new rims, go for it.
And
www.flatlandfuel.com is the only place to buy it.