Hey Nick, sounds like you're doing the right things.
As for a timescale, i went to the AFCO in Sept '06, then went down to RAFC for the NCA Brief in October '06, had my filter interview in January '07, went through OASC in June '07, and i'm due to attend RTS in 3 weeks (October '07), and hopefully NCAITC come January '08. So it can be a bit of a wait, but i'm sure it'll be worth it, and it certainly allows you enough to prepare for selection.
Good luck with it all!