It realy doesn't matter what size spot you're getting into,there will be a tool for it.
As far as RPM, their are 5000 rpm tools out there.
Generally speaking, for occasional usage ,a cheap one will do.
But ,this is a product you get what you pay for. Dotco and Cleco are near the top of the line,also Dynabrade. 3M now has a line of air grinders.
I also find the Right angle tool to be the most versatile,and some can be coverted to regular die grinders.
