Whats the Best Digital SLR for me?

For the past year or two i have used my parents camera, a CANON EOS Digital Rebel XTi, and ive loved the results until a few months ago, i focus on animals and plants, so i go to horse shows, and the last one was indoors, and i kept getting either dark pictures with no blur, or grain-y pictures with major blur. Only a select few turned out decent. All were trashed. I checked the aperture n everything, i used every setting, i got varied results, but none worked. Im probably an intermediate, and im just starting to really get into ISO and Aperture and such, but i know what im doing. Im looking for something that is durable, takes good action shots, and has some point-n-shoot. Maybe video. Im just looking for the camera n come with lens, and maybe in future years ill buy a macro n such. Any ideas? My max. spending amount would be $850, if that. Any suggestions, reviews, or sites that can supply me with such? thanks