http://www.pso-world.com/forums/showpost.php?p=2398551&postcount=18
So it looks like SEGA can afford allowing extra collaborations beyond the UMD space. Might I make a couple of suggestions (though not wholly inclusive):
CHAOS;HEAD
- All the Di-Swords as swords, except for Rimi’s which would be a Twin Dagger
- Suimei Academy uniforms for men and women. Women would have more variations, particularly in choices like stocking colors, etc.
- Seira-tan’s outfit, pre and post-awakening versions
- Possibly Rimi’s “Final Attack” as a Photon Mirage? Doubtful
- Hair styles covered from CHAOS;HEAD not already covered by PSP2
.hack
- Kite’s Twin Daggers, Haseo’s X-Form Twin Daggers
- Data Drain Bracelet as a Photon Mirage
- All 8 Epitaphs as MAGs
- Hair styles covered from .hack not already covered by PSP2
Sadly, I cannot think of anything for Steins;Gate. Despite it having a story x1000 that of CHAOS;HEAD, it unfortunately would not fit… 
