Zoom or Prime?

FWIW you need a second body (nothing worse than having an assignment and no tools to produce results with if your primary body fails) and a decent zoom lens or two....don't discount the 50 1.8 to have as a single prime....for the price it could be a handy lens to have on hand.

I have the 70-200 f4L....its a good lens, and unless your light is fairly low its light and easy to handhold.

Well, you have two choices IMO.

2 bodies or a 70-200 2.8 zoom by Sigma or Canon. The only way you can really make that 200 2.8 versatile is with 2 bodies IMO, at least if you can't control the situation as much. 70-200 f/4 is out of the question to me, because it puts too much strain on you, in the sense of not being versatile for your gigs that you will do, without a monopod or tripod.

That's why photo journalists use zooms, generally. (16-35 2.8, 24-70 2.8, 70-200 2.8 w/ 2 bodies).

Should add, that since you would get paid for it, a second body is good also just to prevent the chance that one body dies on you.

Hope that helps.

Fair enough - I guess my main concern is that I will get a fast enough zoom for places where either I won't be allowed to use my flash (the awesome Metz 54 MZ-3), or the range will be too great for it to work.