I KNOW I'll get a ton of hate for this but I actually enjoy Yareli and the whole K-Drive system. I think for Yareli Prime and a really awesome accessory would be a primed K-Drive skin. Since she'll get Merulina prime, I think it would be nice for the rest of my primes to be able to skate around in good ol' prime style.
I also would LOVE if we could get a Vasca Kavat prime gene masking kit and some kind of prime skins for the Predesites and Vulpaphyla. I love the prime kit that came with gara prime, but it doesn't really give off the vampy vibe my vasca kavat has. And I think the infested companions speak for themselves when I say they need some skins.
Just my two cents on some fashion I'd love to see in the game and I'm sure there's others out there who would agree!