Hi Danic,
If you think only buy for photoscan without doubt the best option is Geforce. GPU acceleration is supported for geometry reconstruction step only.
The Quadro line is a range of professional applications that need such OPENGL_STEREO and sophisticated renderings. Thus are not comparable video cards, but for your specific question, for use with Photoscan the best option is the Geforce, just look at the specifications of each card:
Nvidia Geforce GTX 590 vs Nvidia Quadro Fx 4800
1024 CUDA Cores vs 192 CUDA Core
327.7 Memory Bandwidth (GB/sec) vs 76.8 Memory Bandwidth (GB/sec)
No Stereo (3-pin Mini-DIN) vs 1 Stereo (3-pin Mini-DIN) (OPENGL_STEREO)
Regards,
Diego