Best kernel sources for 2.6.36?

Personally, I use vanilla (that is from kernel.org) kernels all the time. It’s least work (no applying of patches) and it always gets you a recent kernel (no waiting for debian patches to be ported). They simply work, but keep in mind that there are currently quite frequent security updates and it is a bit harder to recognize which updates are for security. Also if you run into problems with your kernel, the kernel folks are usually more willing to help if you run a recent vanilla kernel.

A clear disadvantages for the other options is that you are using an untested configuration. Also keep in mind that the patches might fail to apply or introduce subtle bugs, since they expect a different base version. I cannot really comment on the advantages of the other options, since I never tried them.

To me it really sounds like bike shedding. I have pointed out some (biased) advantages and disadvantages. I doubt that any of the approaches is flawed, so just choose the one you like most.