Ay up Stempy,
This may be of use to you...
http://www.z1enterprises.com/Z1CarbGuide.aspx
Scroll down to bottom of page.
I've got 720 big bore kit in my 650, 29mm Smoothbores, K&N, Pingel hi flo, Harris 4-1 and just been to Projex in Cradley for a Dyno and setup.
Ended up with 25's and 120's.
Running great!
Cheers,
Bongo.