Exch2K replaces Exch5.5

I have one w2k DC server, NT4.0 BDC with Exch5.5, only 40 users and ready to buy another w2k for exch2k. we don’t want to keep any exch5.5 structure, and currently users keep their PST files.
My plan is to promote the new box as a DC and fresh install exch2k with a new organization and site name, and copy PST back to new mailboxes on clients. Also physically disconnect exch5.5.
Please advise if it’ll work or any potential problem.
Thanks