Let me preface this with saying that I am a tool junky and I hate sanding. Sanding tool needs are project dependent, Intarsia calls for different than say cabinet building.
But for general scroll work my most used tools, started with a Random orbital, replaced with the SandFlee with a Mac mop on the end shaft. 1" belt sander with 6" disk .Disk replaced by a Delta 12" disk sander.
I got into Intarsia, Built a 6" pneumatic drum sander 2" on the other side, Jet Oscillating spindle sander.
I cut and need lots of thin and different thickness woods so I now have a Supermax 1938 drum sander. It along with the Sand flee get constant use.
Power sanding requires good dust collection!
I know, over the top, as stated above a good belt disc combo, a random orbital palm sander an a mop sander will take care of most of your needs, Add as your needs change.