Laptop Refresh

Hi, We are about to refresh about 250 Dell D610
for Dell D630.
Can somebody point me into the right direction
of what software do I have to use?, what
hardware is the best?, Best Practices?

We are moving from Office 2003 to Office 2007,
Lotus 6.0 to Lotus 8.0 , XP will continue to be
our OS.

thanks