If my memory serves me right minus the oldtimers the fella I talked to at Rc Components was Eric. Dont quote me on it but if you were to give them a call I am sure they will suit you up with the proper adaptors.
When I explained to him what I was in need of to go from the 2000hub to a 99 pulley he asked my address & shipped me the adaptor for nothing. Quite a nice gesture by him.
It would be alot cheaper than buying new hubs & besides you have the sealed bearings which are a blessing as well.
As far as the teeth on the pulley you would have to count them on your 99 pulley to see if they are the same otherwise you would be into changing final drive ratio & a different width belt if they infact vary.
I can associate with the mock up to see first hand how everything looks & fits. Its all part of doing a ground up build.
Depending on your rear riptide rim will determine the proper spacing & the size of tire you will be running. I know of moving the rim over towards the right side & getting the caliper milled but that is only needed if you want to run a 200 series tire in the back
How wide is the rear rim & what diameter?? Take yer time & it will all come together.
As far as finding a riptide frt rotor ... you may fall into one tomorrow & then again you could never find one.
I am presently trying to find a Carriage Works Rear 'Hurricane' wheel to match the one I have up frt but to no avail as of yet. If you ever come across one let me know Ill post the picture. If I ever cross paths with a Riptide rotor you'll be the first to know.