So because I keep seeing cool ideas and then promptly forgetting them I'm going to try and keep a rough archive of neat ideas I'd like to do here!
1) Slaves to Darkness Chaos Chosen warriors of Slaanesh - convert using the Sisters of Silence kit with swords; add heads/arms/bits from deamonettes
2) Use Daughters of Khaine parts/heads for Harlequin riders/troops in 40k
3) Use high elf Phoenix wings for Mind cat - link also has neat leopard paint tips.
4) Everqueen wings for wings on a demon prince (going to be darn hard to find those wings on their own )
5) Mind cat head used on a Keeper of Secrets. Use spare head for a spare part swap - add legs/tail end to make even more feline keeper.