if a video card has vga + dvi out, it always support dual monitors?
Only if it has dual RAMDACs, AFAIK. A RAMDAC is required for an analog output, which is what the overwhelming majority of CRTs and TVs accept. The card you linked has dual RAMDACs because the DVI connector is DVI-I (you can tell by the cross with the holes in each corner on the right side of the white DVI connector), indicating it can support a second (analog) CRT with a DVI-VGA adapter. DVI-D (no cross), on the other hand, can only output a digital signal, thus only support an LCD with DVI input.
A cheaper card that will do some 3d, but the focus is on 2d quality that will do dual CRT's at 1600x1200....
Dual CRTs at 16x12? I'd probably suggest a Matrox card of some kind if you want the highest probability of crisp text on both of those high-res displays. Either that or consider dual cards, one AGP for 3D and one PCI for the second monitor. I'm not sure many "cheaper" cards will offer crisp text at 16x12 on one display, let alone two, but I don't have much experience with video cards and CRTs at that high a res.