ughhh.. i love my FLU but for a little extra money the BLU sounds so much more worth it (I'd love to trade up!), or maybe just take the plunge for GP2X.
to reiterate, FLU was great when it was all there was, but for longevity's sake I'd recommend something else (esp. one that's not broken!)
The FLUs were modded with a type of Afterburner light guide. Hahotech did them for Gamepark, and I don't think you can get just one single light kit from them ... better off getting a BLU or BLU+