Which camera is best for equine photography?

I have been looking at purchasing a dSLR, and I think now my search has narrowed to the Nikon D60 and the Nikon D70. Which camera would be best for equine photography? (both close up stills and high paced, high action work- like horses jumping). I would also like that it be able to handle low light situations- like indoor arenas. Any lens suggestions also? Feel free to suggest other cameras that might work for my needs.

Those cameras are quite old.

They have been replaced by the D7000 (D70 after three updates, D80, D90) and the D5100 (D60 after the D3000 and D3100) although you can shoot perfectly fine equine images using those older cameras

Look at the D3100 as your camera of choice.

What is most important is the lens you choose. Shooting equine or any action photography from the side lines has more to do with the lenses you own. I would suggest that the Nikkor 70-300 mm may be the best lens for shooting what you want

A Horseman of course!
Or an Agilux Colt. You could even consider a Hosselblad!