Originally posted by marcdsgn Thanks so far, everyone. Just got into work again, so I've only just read all the posts.
I've made a note of all the models you've mentioned so far. Will check out any reviews I can find.
Keep the advice coming... The more knowledge I'm exposed to, the better the decision I make in the end.
The D80 is very comparable to the K10D in image quality and overall features. (I know as I replaced my K10D with a D80.) The D80 does have "scene modes" and other features intended to attract point and shoot cross-overs, but it is a quite a good camera with very good image quality, excellent AF speed and accuracy (with fast AF-S lenses), good penta-prism viewfinder, etc.
If you are comfortable with the price of the D300 at about $1625 (body only), then go for that as it offers better construction, slightly better resolution, better AF, better high ISO performance, and other extra features. It is definitely the sweet spot in the current Nikon semi-pro to pro line-up, in terms of price versus performance.
If you want to use manual focus lenses, you need the D200 or D300 (or better models) as manual focus lenses will not meter with the D80 or D90 (or lesser models). The D100/200/300/700 semi-pro series as well as the D1/2/3 pro series will meter (even matrix meter) with any "AI" or later lens and support any exposure mode that the lens supports. However, you cannot mount any pre-AI lens on any Nikon digital SLR and may damage the camera if you try to do so. So if your wife has any *really* old lenses check them out before trying to mount them.