Before I even get started, I know these threads have been debated to death, but nothing I searched for suited my specific needs, so I figured I'd try my own thread and see what I got.
Now, I shoot with an Xsi, and I don't dislike it, but lately, I feel that I may have outgrown some of its features. I'd like a bit more ISO capability, better AF tracking, and the general bad-assedness (yup, it's a word) of the 7D.
The dilemma is this: I'd also love to upgrade my lens bag. I only shoot a 17-40, 70-200f4 and a 50 1.4, and I definitely have room for a longer lens like the 100-400 or the 300 f4 prime in my kit. I know, I know, it is a glass first world for the most part, but I'm having a hard time deciding which to upgrade.
I generally shoot landscape and nature, but more and more I have friends roping me into portrait work and paid gigs shooting parties etc...
So, please give me some guidance here. I'm all ears. Oh, and as much as I wish I could upgrade both, I can't, so don't toss that out as an option. I'm a teacher and these things tend to come one at a time 
Thanks for the help
-Mike





