CrazieCricket - your situation doesn't sound all that different than mine. I'm an average-sized woman (well, I could stand to lose a few pounds
) and have relatively small hands. I purchased the 450D about two months ago and have 4k+ clicks with it. I've got a wide selection of lenses, as my husband has been collecting Canon toys for years.
I chose the 450D because of the size ... I was moving up from a Panasonic FZ-50, and was really turned off by my husband's larger camera bodies - thinking they were too big for me. I really like the 450D, but found that I was using the EF 100-400 L and the EF-S 17-55mm f/2.8 on the camera a lot - mostly on a tripod. I also picked up the EF-S 10-22 f/3.5-4.5 for landscapes. While the larger lenses work fine with the 450D, they do seem a little off balance.
Bottom line -- I realized my decision to go for the 450D, based mostly on size, was the wrong one. I'll be doing lots of birds and some sports, so I've just ordered the 40D.
Note that I still think the 450D is a great choice, and the 18-55 IS and 55-250 IS lenses make a great combo for a good price. But, the 40D is probably the better initial investment if you know you're going to be serious about the hobby. I can't confirm I've made the right choice this time around, as my 40D doesn't arrive until Tuesday. Didn't mean to give you my life story, but was struck by the similarities between our situations. Good Luck with your decision.