Like I said before, just order the unit from FBF. If it's in stock, they should have it to you in less then a week. The maps they provide are for different exhaust and airbox setups.
The Power Commander site does not list the '02 620 but, the box provided by FBF mates up with the connectors on the bike and works. I don't know if FBF does anything to the PC. If they don't you may be able to use the PC from the 800 Sie.