Hello and welcome to Linux CeeJayCee,
Here are my thoughts about the questions in your post.
I purchased SUSE 9.1 Professional Upgrade. My understanding is that the SUSE Personal Edition contains 2 CDs and printed documentation. One of the CDs was the Live CD and unless it has been updated, a version that has a security flaw. The second CD is the install CD that is now available for download. So the question is if you want the printed documentation and do you have a few bucks to throw SUSE's way.
The single Personal install CD has far fewer choices of programs than are available on the Professional version. Besides being a question of some favorite program of yours not being included, it does not include any servers. Not a big loss for a lot of people, but nice to have available.
SUSE is also available as an FTP install. This is free and has all packages available that the Professional version does. If you have a fast internet connection you may want to investigate this option.
There is also the option of choosing the site that YAST will use for package availability and updates.
Check this excellent post
for one way to do that.
The summary goes something like this. You can test drive SUSE without spending any more money if you wish. You may want to ask yourself if you want printed documentation. You may ask yourself if you want some of your money to go to SUSE.