Thanks for the replies everyone.
First of all thanks again to our generous equipment suppliers, Birdy & MCBW.
I stuck the SB800 on ordinary TTL
mode, camera on matrix metering (I would normally use CWA but with the Kiwi players in black it gets thrown off), ISO1600, AF-C and continuous shooting.
Any advice on how to use the flash effectively would be very much appreciated, as we've been thrown in the deep end here

. I wanted to use a lower ISO, but it meant that the flash was doing all the work, leading to dark backgrounds, and more importantly, slower recycling times, which is a big problem when you're trying the fire off sequences at 3FPS.
Shooting portrait is easier to fill the frame, but not easy to maintain with a D70s, SB800 & 70-200VR. I would kill for a battery grip option for the camera, or failing that, much stronger arms

. It's fine for a few shots, but gets tiring on the wrist after that. Also, using a flash, you lose the ability to follow the action with your non-shooting eye.
Any more advice or suggestions welcome
Edit: shutter speeds with the 70-200 were ~1/100 up to ~1/300. The 84/1.4 got 1/400 up to around 1/640 occasionally.