As far as 3d modelling goes, you will need a nvidia card.
Currently the gtx 690 is the best single gpu available in the market.
It costs ~ 65k in India. However if u can get it from newegg or so, it ll cost u ~55k
Other option - gtx 680,gtx 670.
You can opt for a workstation class card (quadro/firepro series) for 3d modelling and rendering but it wont help u in gaming.
If we take most of 3D applications into consideration and also gaming into account then GCN-based HD7000 series card are much better than geforce cards.
But then exceptions are there like applications like Blender which still now don't have proper support with AMD cards.Blender 2.62(if I remember correctly) introduced OpenCL support but the performance with OpenCL went down from 2.62 to 2.63 with radeon cards i.e. thay are slower in blender cycles,still in blender viewport rendering radeons are faster.
For MAYA GCN cards are better if one wants gaming too.
Overall GCN cards are much better than geforce counterparts in compute department.
As far as professional graphic cards are concerned,in India upto 20k firepro cards offer much better performance than quadro counterparts in most of the 3D rendering and compute applications.
Firepro V3900,V4800,v4900 all give better performance in most scenarios than quadro cards in the same price range.Quadro 2000 which costs around 26k is a good looking card for 3DSMAX but if we take MAYA,lightwave and some other applications into account then firepro v5800 is a better choice.
V4900 is quite a good card if one can find one,performs close to v5900 in some scenarios.
Cards should be chosen specific to applications that one would use.