Windows 2K does have the best thread management of any recent OS from Microsoft. If you are running a dual core CPU and can get Win2K drivers for the motherboard, I would fo with it.
I am not sure you can even get any of the updates for it though, from MS. If not, then it will not be a good choice due to the bugs in the early releases. In a lot of ways Win 2K is a much better OS than XP.