Changing an XP network to Win7 with SBS 2003

We have 30 computers all running XP, we are now due to replace them as they are 10 years old. Would I need to update my Server OS from SBS 2003 before installing Win7 on the clients ?

I know the proper procedure is to upgrade all tech together, back end through to front end, but would SBS 2003 handle and function at 100% ? If I go for an upgrade on the Server OS I would need to upgrade the server hardware to 64bit.

I can see the ££££s stacking up !

According to Windows support there will be some updates required for the server. The link below explains the updates required in great detail.

Windows Small Business Server 2003: Windows 7, Windows Vista and Outlook 2007 compatibility update