Jim,
you are likely to get much less variation in performance on TFT's than you did with CRT's - With CRT's a cheap tube was never going to make a good monitor, there are relatively few manufacturers of TFT panels, leading to less variations between manufacturers..
Resolution-wise, TFT only works properly at it's 'natural resolution', for a 17" that will be 1280x1024 - if you try and run at anything other than the natural pixel pitch the display will be very fuzzy, as it has to interpolate between pixels and essentially fades one to the next.
If you want to do games then bear this in mind if the game forces a particular resolution. Also for moving image you need a panel with a quick rise time (the time it takes a pixel to change from black to white) this is normally specified in milliseconds, anything under 15mSec will be fine.
The Image quality is strongly influenced by the Contrast Ratio - anything over 450:1 is fine.

Don't get too hung up on DVI compatibility - you will pay extra for this and whilst in theory all things being equal, DVI should give a better image, in practice with a decent graphics card analogue you will be hard pushed to visibly see the difference.

I've got a GNR 17" - http://www.gnrintl.com/products/f173.html - probably never heard of them? LOL.. but uses a Samsung TFT panel, and is as good as any other I've seen (would normally recommend Iiyama from experience), as an example these are around £240 incl.