I asked you why you posted where you did and you didn't bother to reply.
You can't upgrade your USB ports. If they are USB 1.1 then they stay that way.
Win2000sp3 isn't going to be any slower than sp1. If you are going to use Win2000 at all you should be running sp4 with the post sp4 updates. The service packs in Win2000 added many enhancements over the years. Better USB support, large hard drive support are just two.