From the FAQ thread

wheel lug spacing and offset

any wheel with 5x114.3 or 5x115 bolt pattern and 38-45 mm offset should work just fine for the 97-03 GPs.

Offset is the flat face where the wheel mounts to the hub and the distance to the inside edge of the rim. The higher the offset the deeper in the wheel will sit, the lower the offset the shallower the wheel will sit.