Windows 2000 Terminal Services Licensing

Hi,
i have an issue with win2k terminal services licensing. i am about purchasing licenses for my proposed client but in the mean time my network is workgroup based and i intend to use TS immediately infact i have started on the 90 days grace period.
i am looking for a solution to implement my licensing without disrupting my present network and which will serve me when i upgrade to a domain structure as well