There are all sorts of potential pairings you could try with ghost motleys. The snow stripe and Sunkissed pairings are terrific suggestions. You can also try a bloodred pairing (hypo blood, anery blood and amel blood are even better) to eventually produce ghost motley bloods plus. Adding lavender would also give wonderful results (hypo lav, lavender motley or lavender bloodred to add even more possibilities). Even adding caramel would be great (caramel motley, amber motley, caramel bloodred, etc). For the ultimate, something from the lavender caramel "mystery" pairings would also work.
The choice is yours. IMO, ANYTHING goes well with a ghost motley!