Fein Multimaster is the nits. I was thinking of suggesting an angle grinder when someone mentioned the Fein. Odd, since I have one, I should have known.
In any event the Fein is $300 smackeroos. That is due the patent they owned on the product for the past decade. That patent wore off last year, there are now much, much cheaper versions made by bosch, dremel, rockwell. All less that $100 I think. Not as powerfull as the Fein, but will do exactly what you are trying to do. I believe the Rockwell gets the best reviews
. And their kit comes with a lot of blades, (which are pricey at $15 ea.)