Hiya Lori,
I guess I am somewhat of an expert at scanning paintings since I have scanned everyone of my paintings including every painting on these two sites:
http://fineartamerica.com/profiles/charles-moran.html
http://fineartamerica.com/profiles/lu-kimmel.html
What Murray was talking about is called "Tiling". That's what has to be done with the larger paintings. They have to be scanned 4 to 8 times and then tiled together. The program I have used and still use is "Photoshop" which, unfortunately, is one of the most expensive graphic programs you can purchase. Now, it's even worse, you have to lease Adobe Photoshop by the month. Also you have to join their club before leasing the program. Sometime a couple of years ago, Adobe saw how much money Comcast is getting for their TV provider and decided that they weren't making enough money off of their programs so now, you have to rent them. Go figure!!! Thank God I can still use my old photoshop programs to do all of my work otherwise I would be forced into renting their programs too. My problem is I can't upload or upgrade any new programs because that would make my old programs incompatible to the new ones. Sooo, the trick is this, if your computer works well with all of your "old" programs, then don't upgrade them.
Unfortunately I am not familiar with the other programs that they are talking about.