still need to select a graphics card

I am still trying to figure out which among the many OpenGl graphics cards have the features I need:

(1) direct rendering for Windows and Linux (meaning direct rendering drivers are needed).
(2) 3d texture
(3) alpha blending (for transparent surfaces). Apparently I can expect this in most cards.
(4) If I can get it, 4 user over planes (which is standard on SGI Irix systems).