A fast graphics card with 512 MB storage, like 8800 GTS 512MB (G92 Chip) or 9800 GTX 512 MB (watch out - a long card to fit in your PC - 26.7 cm length ) or GTX 260 / 280 any RAM amount - they all are good or good enough for Vue - since the normal 3D-view windows should be using OpenGL and not DirectX ... and the influence of graphics speed of the newer generation of cards isn't that important for the OpenGL calculations - they don't use the shaders as speed-ups, just raw GPU calculation, because it's a system, that suppose to work on a lot of platforms and graphic card solutions - so - no special stuff is used, meaning the difference won't be too different between newer/older or slower/faster cards ... 

For Vue it's more important to have more then enough normal RAM on the mainboard - which is limitied by a 32bit Operating System with Windows to about 2,5 GB per program.

A 64bit OS can use a lot more RAM per application ... here is an advantage in the use of Vue, not really by having 512MB or 1024MB Ram on the graphics card.

And looking for a quite cooling solution without a fan - well there should be mostly only the smaller version of the graphics cards like the 8500/8600 or 9500/9600 versions as an option, because cards like 8800/9800/260/280 are running on a lot higher frequency and using much more shaders than the smaller cards, so they would get to hot, if not using a fan for cooling.

The GT / GTS / GTX and so on extensions are mainly pointing towards the use of higher GPU frequencies and the use of more shader units inside the GraphicsProcessorUnit or different generations of the same GPU - which means more heat will be produced under full load.
But that only happens, if it's used for the display of fullscreen animated 3D-stuff in realtime, like detailed 3D games ...

Nice to see, that the newest Photoshop version CS4 will be using, for some new functions, as a first time the graphics card GPU instead the CPU !
In Photoshop CS4 it will be interesting, to have more graphics card Ram, since it really get's used there ...

So if not playing games and wanting fanless cards - i guess then a 9500/9600 version would be fine with 512 MB. Pretty cheap, too - should be around 100 $  or less.

But there are still nice ATI cards around like the 3850 / 3870 or newer 4850/4870 ... fast and good, too.