Currently there is no official bike, but here are the recommended specs (courtesy of West Coast Gold Sprints) if you are going to buy bikes:
Frame size for all bikes: 53cm
Handlebars: Uncut Bullhorns
Seatpost: 420 mm
Gear ratio: 53:12 fixed gear
Rear Hub: Fixed/Free (Flip Flop)
Seatpost Clamp: Quick release (with many backups)
Having a small frame size, bullhorns with multiple positions, and a really long seatpost capable of many heights makes for ONE bike that fits LOTS of people.
The gear ratio is steep, which delays racers from spinning out and separates the strong sprinters from the rest.
Yes, pedaling backwards on rollers using a fixed gear will cause the bikes rear wheel to fall off the roller. But going fixed keeps the racers steady.
For non-competitive events, aka you were hired as entertainment for a corporate party, flip the bike to a freewheel to eliminate risk with new riders.