Hard to tell from that pic, but that looks like it might be the same quiver we have currently just pure black (no skin.)
I think the quiver we have now is a bioware thing not a custom job.
The only other quiver mod I know about is the.. I think DLA quiver, which puts the quiver mod on your back whenever you have arrows equiped. That quiver is of more appropriate length, but the sytem that puts it on when you have arrows equiped is a bit funky I think. I also seem to recall L saying he was against using it.
On this topic, I kinda wish there were more "accessory" models available. Like, longer quivers, hip quivers, scabbards of different lengths, and especially a scabbard like a pirate scabbard, or 3 musketeers scabbard. You know, that hangs vertically from the hip for a rapier or sabre.
Anyway, now I'm thinking about it... gonna go see if I can find anything cool on the vault.
-TV