The current environment is 9 workstations (desktops, laptops), 3x Mac OS and 6x Windows and a server running SBS 2003.

For the Windows machines, a few are still running Windows XP Pro, 1x Vista and a few on Win7 now.  They are all are using Office 2003 pro (appear to be retail versions) connected to Exchange 2003 (SBS 2003).

The Mac machines are all fairly new running 10.6, they appear to be running retail versions of office 2004 for mac.  For email the connection to exchange 2003 is via Apple Mail using pop/smtp.. I presume this is because Entourage sucks and Exchange2003 IMAP performance is pretty bad/buggy with Apple Mail clients.

So lets say we need:

SBS 7
3x Office 2011 for Mac
6x Office 2010 for Windows 

They don't need any new hardware at this point, there is enough tech savvy for installation and configuration to be done in house but it could be contracted out to a IT services company if the cost vs time saving was worthwhile.

They are not currently a MS partner, looks like they had an action pack back in the day when they were a larger company before one part of the business was sold off.  

The inhouse developers have an MSDN subscription for their stuff so that covers Win7, VS2010 and SQLServer for 2-3 of the windows machines but of course does not include Office.

I've suggested Google Apps and BPOS/Office 365 but given the size of attachments they deal with and size of existing mailboxes, increased international data usage they are not keen.

So my question is really what is best way to acquire the licenses they need?