I think you will find that all DA sanders will require a lot of CFM to run. You can getaway with running one on a small compressor but only if it was for a small job and for short bursts at a time. To run a DA (or any other high demand air tool) you need a high CFM and a good size receiver (tank).
If you are looking to run a compressor off a Honda generator? (If I assume correctly) you will struggle. I would say you would be looking for 14CFM as a min to run a DA and 3hp that is also about the max you could run from a single phase supply. And that is recommended to be hard wired into a 16A supply.
I have a 14CFM and 150L tank compressor in my garage and the house lights dim when it stars up.
If you are hiring one you could hire a stand alone petrol one which should do the job like this unit http://www.machinemart.co.uk/shop/pr...ven-air-compre
Let us know how you get on?