I don't think you'll find anything lighter and as good as the PSR3000. I owned that board and it was a great improvement over my previous PSR2000. I don't know if Casio has anything with the 3000's features, but they would be your best chance at a replacement. Everything else is bigger, heavier and probably has less features. Good luck.

BTW, I used a RokSak 61 bag for my 2k and 3k. It fit snugly over the 3k and I sold it with the board.