comparing hardware architecture

[Marvin L]

Currently, I have two algorithm to consider.

one using FFT, one using DCT
the DCT is using NEDA
for FFT, I am not quite sure which one to use

Do you guys have any suggestions for FFT and DCT regarding implementation ?
I am now reading on NEDA and Radix.

Besides, how would you guys implement DoG (Difference of Gaussian) in hardware ?

Thanks !