You're correct that an SN starting with F99 would indicate a guitar made in Japan by FujiGen in 1999 (probably in November). Since it was produced late in 1999, it's likely a 2000 model.
If we look at Category:2000 models, the most likely suspect is the RG680CL. If the description of that model doesn't match your guitar, then we'll need some more details: What pickups and pickup configuration does it have? What color? Is it solid color or does it have some sort of exotic (flame, quilted, etc.) top?