Upload & Sell: On
when I entered the DSLR world a couple of years ago, I chose a camera with weight in mind, as long as it had a decent set of specs. I chose the Nikon D5000 and it's stood up to a year+ of unexpected newspaper work. The 'quiet' shutter setting is a bonus... I've been in performance audiences and had people tell me they didn't hear a thing @ ~4 feet away.
Its light, not quite as light as an non-mirrored setup, but you'll retain a good amount of control for a small amount of weight. A used D5000 with an 18-55 kit lens will cost you under $500US and is about as light as you can get in a true DSLR. And you'd be able to shoot video if the mood strikes you. The upside to the 18-55 kit lens for a setup like you're looking for is the downside to most... its plastic and a 52mm diameter lens. Sharp, too. My copy is fantastic at the wide end.
The 'vari-angle' viewscreen seems really gimmicky, until you want to compose in LiveView with the camera over your head standing on a rock to get line-of-sight over a tree branch. Then its not so gimmicky.
I'd love to sell you mine (hehe) but I probably have to use it tomorrow.
edit: If you take my suggestion seriously, I have two things to add. #1. Get the D5000 over the D5100. I haven't shot the D5100, but I held one in a store, and I much prefer the vari-angle setup on the D5000. I don't like the way the D5100 switched to a side-out swing. It just feels less forgiving in regards to breakage. #2. Look into the M-Rock line of camera bags. They are really sturdy and probably the best protection-bag available on the market... especially for a single-lens setup.