eddx said:
What do you recommend? Nikon or Canon? and why?
The camera doesn't make a whole lot of difference overall. The decision is really "where should I spend my money lens-wise?" Subjectively, I prefer the contrast of Nikkor lenses to that of Canon, but image quality wise, my Nikkor 400mm 2.8 lens is not a great deal different than the same sized Canon lens- you'll find that most people who hold opinions haven't shot with both systems. I find Nikon's bodies more intuitive, but then I've been using them for a very long time, I doubt it's all that much of a deal killer for anyone looking to do pro-level work where you're mostly shooting from support anyway. Nikon's flash system is superior to Canon's, but if you're going to do off-camera strobes, that won't make much difference. Canon's high-ISO noise is less, though it seems more due to programming in camera than the sensors. Nikon outsources its sensors to Sony, Canon doesn't.
Glass-wise, if you're just going to get a couple of small lenses, then go with the system that has the lenses in the range you want to shoot in. Spend as little as possible on the body and as much as you can on lenses, they make the most difference.
Canon's long lenses (the ones that cost as much as small cars) are all image stabalized, Nikon's aren't. Canon's long glass is cheaper than Nikon's.
With a few rare exceptions, 3rd party lenses suck in comparison to the OEM lenses unless they're made by Zeiss. Also, OEM "pro" lenses hold their values a lot more, so you don't end up eating the full cost if you need to swtich.
If you know photographers with one system or the other, and they'll let you borrow their glass, then go with that, otherwise find a store with both bodies and a fair selection of lenses and give them both a try.
Paul