Most of this is hearsay so bear with me.
NERD compatible w/ VPI
D&M compatible w/ SK
Also Jollif has been proven to not be compatible with VPI (there are double hets and possible double hets running around).
On record the only SK to VPI breeding was het to het. 6 eggs. No Axanthics. Long odds to say for sure that they aren't compatible. I had heard Graziani and Micheal Cole were going to try homozygous to homozygous breedings to prove it out for sure this year but haven't heard how that's going.
Overall I'd say the best axanthic line is buying into a particular animal that has the coloration you are looking for, a good price, and is from a reliable source. I think if you do that you'll be very happy with whichever line you choose