Retrowood,
Regarding the sanders, I'm not an expert. I have an RO150FEQ; I'm ordering an RTS400 and LS130 today. And a bunch of Festool abrasives. I think the general consensus is that the Festool sanders are the best available.
Regarding the abrasives, they have an extremely wide variety of abrasives. The quality is very high and what is better is that they have the same abrasive for a wide variety of their sanders.
First, take a look at Jerry Work's Festool sander document:
http://www.festoolusa.com/Web_files/Getting_the_most_from_Festool_sanders.pdf. This will help get a better understanding of the sanders.
Second, look at the Festool abrasives catalog here:
http://www.festoolusa.com/ProductDetails.aspx?id=7&prodid=571536&tab=access#. This should answer many questions about what is available and for what use.
Third, take a look at Forrest's list for sander and abrasive reviews and other info:
http://festoolownersgroup.com/index.php?board=19.0. (Forrest's Consolidate List of Festool Links is probably the best list available for worldwide Festool info.)
Good luck with your decisions.
Dan.