No issues with the 6800. Everything seems fine, although I haven't yet tried the Quake 4 demo, so I don't know exactly how well it performs with the Doom 3 tech. HL2 seems great aside from the stuttering problem on level loads, which is not a graphics card issue.
Quake runs REALLY nicely at 1920*1200 widescreen (thanks Metl... I love you).
Oh yeah, make sure you get a 256mb graphics card! 512mb is perhaps overkill, and a bit expensive atm. There are also only a handful of cards with this much memory.
I don't know the difference between LCD and TFT. I think TFT is an acroynm for both CRT flatscreen displays (Truer Flatter Tube) and also for the current type of Laptop monitor displays (Thin-Film Transistor - which I just looked up on wikipedia). It's all a bit confusing for me.
I think LCD means current flatscreen TFT technology these days, since no modern laptops use LCD displays.
Anyway, yes, CRTs are better for gaming, but LCDs are really light and thin, sometimes easier to look at for long periods of time and can be good enough for games that there isn't really much difference between them and a CRT. If you don't mind 10 tonnes of monitor cluttering up your desk and want to save a small amount of cash for ultimate image quality, then a good CRT might be better for you, but personally I'd find a good LCD (short update time, good at resizing images, clear, low reflectivity etc.) and get that instead.
Anyway, I just had a quick look on
http://www.overclockers.uk (hardware site) and they barely have any CRTs these days... just two. They have tons of LCDs though, and the prices are not too much higher, unless you want Apple 23" screens*.
Also, when buying a new monitor bear in mind that a 19" CRT has only an 18" visible area, and that a 19" LCD should be 19". Also, you don't need to fuck about configuring a new LCD (width, height, refresh, trapezoid, moire etc.) as they should pretty much just work out of the box.
Finally, I know this isn't much help, but I really would have a look at reviews on the internet once you get a rough idea of what you want, since they can tell you a lot more than me or probably anyone else on this board. Once you have read some reviews and have found what you want, definitely check comments on reviews and forums on hardware sites to see if there are any probs you are likely to have with your chosen kit. It might also be worth letting us all know what you are going to buy, in case anyone here happens to have graphics card X and it turns out to be a piece of shit for game Y.
*you probably need to be a serious Apple fanboy, as they cost a shitload more than other brands. Whether they are better or not, I don't know.