The London Duathlon

I'm thinking of entering this: http://www.thelondonduathlon.co.uk/

Can anyone give me some tips on what I need to do for transition? I assume you don't just wear normal trainers and sit down to casually slip off the Sidis and lace them on?

Also, can I just pop tri bars on my road bike? The ones I've seen don't have brakes - seems very iffy to me.

The extentions are for speed. Braking in this position would be silly, and unstabile.