HS Football help

[sgriggs2006]

Ok, all....Its that time of year again....I am in need of a setup tweak.
I've been putting off buying that $$ glass just for HS Football....but, I think I'm going to have to do it...
My priority for shooting is to get some snaps for the paper that I work for. I have a D700, and my first setup last night was using my 55-200 f4-5.6 (groan) coupled w/ a SB600, ISO 3200 and Manual exposure.....I'm not good enough w/ my timing to rely on the slow recycle time of the 600....I just do so much better w/ a burst of 3 pics, but the flash can't handle that (or, rather,if it can, I don't know how to get it)....
Ok, so I got a few usables for submission, and then I plunked the 50mm 1.4 on it, got rid of the flash and just waited for some sideline action, which usually appears...
The first one is from the first setup(zoom f4-5.6 and flash) and the second pix is from the 2nd setup (50mm no flash)....
I have never used a larger glass w/ lower f/stop number....I am assuming I'm still going to have to use a flash but what to use?....but can you help me figure out my setup?....
thanks!!
s.