There is a product called CrossOver which allows you to run a range of Windows applications in Linux seamlessly but not all applications are supported. It does run Microsoft Office but Access is apparently only 'supported' in the Microsoft Office 2000 version.
For general users moving over to Ubuntu (or any variety of Linux) you do not need Microsoft Office at all. The latest version of OpenOffice, which is installed by default (and free of charge) in Ubuntu, is excellent and I do not think users of Word, Excel and Powerpoint would have any problems making the transition. The database application in OpenOffice is perhaps not so good, however.
In terms of hardware it is usually laptops that present the biggest difficulties because manufacturers often do not supply Linux drivers for specialised devices. This list is a good guide to compatibility with various laptop models:
Laptop and Notebook Manufacturers - Linux Compatibility Status