This is the way I see it: I got this from someone in comp.cad.solidworks.
The rule is not to use a card that connotes violence like Rage, Fury, Voodoo. If you are doing serious CAD, get a card designed for CAD. Get something like the Oxygen or Elsa cards.
Clip->1. Can dual display (output on 2 monitors) be useful in application like SW?
That depends on what it is your building. Like Airplanes - probably so. Huge structures and then you having 2 monitors so you can see it could be useful. But most of the people I know using SW on one monitor will suffice. I build huge buildings and structures and one monitor suits me fine.
So to answer your question....it depends on what you plan to use it for.
Clip->2. Is it better to have lot of RAM on graphic card if I don't use any textures? How much is enough for res. 1280x1024 in 32bit color?
MadMango answer this one well enough but I'll add this to it.
At home I have a 22" monitor :-D (Very Sweet!!) I use 1600x1200 Res. with 32 bit True Color 85Mhz. That is with a Geforce 2 Ultra.
At Work I use an Oxygen GVX-1 Pro and I can only use a 1280x1024 :-( 32 bit True 85 Mhz.
Cheers, Scott Baugh, CSWP

George Koch Sons,LLC
Evansville, IN 47714
sjb@kochllc.com