Going on current and previous form, I would be tempted to have Richardson at reserve. Give him a meeting with added presure and he's done (GP-Itis)
I think for Brandon it would have to be:
Harris
Nicholls
Howe
Stead
Lee / Ed
Don't really think Bridger or Tai (Australian) should be in as it is a big thing for the younger ones, although, with the above team, Lee and Scott are the oldest, the rest are still young and still have a long time ahead.
Olly for backup at Brandon.
Floppy has not really ridden much this season so could be a bit rusty, same with Barker.