I have a couple of recommendations. For less than the price of the Sherlines, you can get something bigger and more useful. There are a number of dealers that stock various mini mills and lathes, but I'll provide the links to one -- Wholesale Tool, whom I have done business with many times, and whom I can recommend. Here's a
page showing a selection of the mini lathes they offer. And here's another
link to one of their mini mills. Unlike the Unimats, these machines are big enough to be useful for a number of different types of work. The milling machine, in particular, is large enough to be useful for a variety of tasks in lutherie.
Crafstman used to make a small table top lathe that was about as big as the yellow and red ones you see in the above link. I had a friend who picked one up at a yard sale for next to nothing. It was very well made, and a helluva find. If you ever run across something like that, snag it!
Best,
Michael