Another thing to consider is that once you chose a brand, it's difficult to change without spending (or losing when selling second-hand) a lot af money.
Me too I chose Canon. I started with a 350 which came with a kit lens I can easily call the worst lens I ever owned.  As my budget and demands are limited, I got Sigma lenses. I love close-up, so the 105 f:2.8 was what I wanted as it goes to 1:1 . You'll be happy with the Tokina also I guess.

Not that I now want to change if Olympus had been earlier, I would have stayed with them, coming from the OM syste), but even if I would want:

1/ my lenses now are canon mount, so I'll have either to stick with Canon or try and sell the lenses
2/ my lenses are for 1:1,6, digital, meaning the 5D and 1D are out of range.

Personally, I see no reason to go 1:1 (the old film size) despite my love for wide-angle - just try (!) to get the quality of a 400D with 24x36 film in 12x17inch prints - but if you think on changing later to a 5D ( or whatever its successor will be named) or 1D, don't buy lenses that are specific for digital camera's as they are unuseable.

My idea is that most brands are good. Don't listen too much to testers. Watch photographs with a critical eye and you'll see that most camera's are like human beings. We're all healthy, but when analysed in laboratoria and hospitals, they always find something. Neither camera's nor their bosses are perfect.
Hold the camera's in your hands, act as if you're shooting (imagination!!!) and you'll get a weak but very decisive feeling. Thrust that.

Have fun!

There are no Borg. All resistance is fertile.