Update: Well, I ended up just busting out the gold card and got a Garmin 800 bundle for her. I figure it's got the most interchangeability with the rest of the stuff I own, which is a definite positive and it has the distinct advantage of being the same thing I got for me. I want to avoid the appearance of breaking the bank on my crap and cheaping out on hers, so the 800 checks that box in a big way.
And... in other good news, I was stuck at some cub scout thing all day saturday with my son and my wife went for a ride all by herself. I did have to explain how to use the pump after she deflated her tires (ever try that over the phone?) but she went and did 12 hilly miles all by herself.