i've got some servers that are currently on SQL 2000 RTM and was wondering how to proceed with updating their patches to the latest versions even though its 2012 the customer is licenced to SQL 2000 so unless they pay for licence upgrades not much else I can do but upgrade patches.

My question is should I proceed on a cumulative basis Ie upgrade to SP1, then SP2 then Sp3 before updating to SP4 and the latest cumulative update. Or would I be able to go straight from RTM -> SP4 with latest CU.

In the past i've kept updates upto date so would appreciate some advise.