i've heard that people are having trouble with the Cuda on the 780ti in after effects etc?
That card is not a card that is supported for the GPU acceleration of the ray-traced 3D renderer.
That said, that is the only feature for which that card is not supported. Unless you care about that feature (which you very likely don't), then that card will work fine.
The GPU is almost entirely irrelevant for After Effects.
Details of how After Effects does and does not use the GPU: