Recommended GPU for FSL DWI processing

Dear experts,

I am planning to purchase a GPU to accelerate the FSL’s eddy/bedpostx/probtrackx2 tasks on my personal PC. Do you have any recommendations for the GPU requirement to deal with a typical DWI data ( with 2mm isotropic resolution & 60-100 diffusion weighting directions)? Minimal information was found except for this post after a thorough web search. Thanks!