Need Help deciding Outlook 98 or 2000

We are having to move from Netscape and Groupwise to Outlook. We are not going to be using a real Exchange Server but a network Appliance that using Outlook for it's client.... We are keeping our Netware 5 box for network services...

So I do notneed nor want all the "extra" features of outlook.. We just want to do email. I only have three our of 30 users that actually use the calender functions of Groupwise. I am trying to figure out if Outlook 98 is fine or if we need or should move to Outlook 2000.... Please let me know your thoughts...