here we go again with Nikon v Canon.
Do yourself a favor, goto the store a real camera store like BH.
Handle the cameras and see what you like the best in your hand. For the most part they are soooo similar in quality it does not matter. I am a Canon person, only because a friend of mine got me hooked on Canon (he has since switched to Nikon, bastard [professional photographer]).
But for end users compare them in your hand and make sure that you compare the similar price ranges to each.
I am also in the opinion to spend the most that you can on the body since you will be able to get more lenses later on (the coveted 100mm macro).
The T3i is def a starter body, so if you can swing it go to the next level (you will be happy that you did, much more functional and configurable). If i would recommend a body it would be the Canon 60d. But I will recommend a Canon just because that is what I shoot.
So in the end it comes down to what is the most comfortable for you to handle. IMO the Nikon has always seemed a bit smaller to me, so if you have a small hand you may want the smaller designed body, and vice versa if you have bear paws you may want a larger designed body.