It'll work, not sure it makes sense, but it'll work. The ExpressCard to TB adapter will cripple the video card to all hell, tho.
ViDock 4 Plus: about $280
Sonnet ExpressCard to TB adapter: about $170
Thunderbolt cable: $50
GTX 760 card: about $250
Why not build a gaming PC on the cheap for better performance and just plain peace of mind?