Dude, I think you've decided about your class 4 card but jic: Either use it for storage only or just send it to a museum. If you try to give it to a homeless person, he'll take 1 look at it and give it back.
Reference the 7D: I love mine. Even though its mainly a back up w/ the type of shooting I do (landscape, portraits). But for anything involving action, I immediately reach for it. & yes, the price will come down. If you have time, keep looking at the Canon refurb site. They're an ok price to start with but they go on sale regularly. 15-20% off is fairly common & a couple times a year they have 30% off sales. Plus, w/ the 70D out they'll probably drop their prices again in the near future. Also call Canon for the CLP price jic the 7D is on the list (should be given the amount of them I'm seeing for sale around).
Good luck w/ your birding & take care!