I agree, get a variable speed motor tool. I bought a Dremel variable speed back in the mid eighties for model railroading and it has been a nice tool. 10 years ago I heard a "pop" and the circuit board fried - I sent it in expecting them to charge for repairs, and then fixed it and sent it back no questions asked. I was impressed. The only thing which wears out is the commutator brushes which are user replacible. So Dremel makes good solid products and only cost a little more.
I used a 2 speed motor tool once but didn't like not having control over the speed. This is something you'll find many uses for over the years, a handy tool, so get a good one and get the kits which come with many attachments too - you'll find uses for most of them at one time or another and it is cheaper than having to buy them separately.