Coffee,

First of all, way to go on your great change of life.
Keep us posted on your physical results.

Second, I ride a Giant Rainier (third season) 1999? model.
I love it. It is a good solid frame that has served me well and rides nice. I haven't logged the mileage on it that I would like to but it has endured all the abuse I have given it. I will, as time goes on and components wear, upgrade to some better components, but the deore hasn't failed yet. The suspension and brake setup on the new models is a step above the Rockshok Judy and the Hayes disc brakes that are on mine and the price is the same as what I paid three years ago. You can't go wrong with a solid bike with disc brakes for $700. A bike definitely worth upgrading as time goes on.
Keep us posted if you get it and post a pic.