Just to underscore what David is saying, you need a fast lens to shoot Agility indoors for any purpose and under flourescent lighting it's even more of a problem. I've shot several Trials indoors under carbon arc lighting and gotten pretty good images but at least they were correctible for color in PhotoShop. Flourescents are real difficult and mixed lighting is almost impossible.

I shoot indoors with a Sigma 70-200 F2.8 zoom at ISO800 and wide open and only shoot RAW which I can then boost for an additional stop in post-processing (also gives you more control of White Balance).

While I wouldn't say it's impossible to get good Agility shots indoors, it certainly is a technical challenge. Good luck and let us know how you do.

Jim