For that concept, Kevin, the piezo pickup would probably work better.  This one here relies on the computer soundcard to supply the teeny bit of power that the condenser mic needs to work.  But something like the tiny battery out of a dollar store wristwatch could do that.

I haven't tried the circuit Oz posted for the piezo, but from what I gather it is intended to drive a little speaker and it has both preamp and "power amp" stages, so that might be all you'd need to get your concept working, right there.

This is just an even simpler and cheaper way to get a signal from a violin into a computer soundcard so a person can quit wishing and start recording.  I would say the main advantage to it is that it actually will pick up the acoustic sound of an acoustic violin rather than making it sound like a sort of electric.  The drawback would be that it would feed back easier if one used it to amplify a violin for performance.  But that isn't an issue if one is just recording. 

Again, there are a LOT of ways this could be improved.  Use an old chinrest clamp to hold a little block of wood on the rim of the violin and mount the microphone to the block of wood with something like a little gooseneck or even a piece of stiff wire, and secure the cable to the block of wood to keep it out of the way and it would start to approach the same principles used in some violin mics that cost a whole lot more.

But just to try it out, a cheapo computer earpiece/mic from the dollar store and a bit of tape is conveniently "entry level".

Good point, peanut_gallery.  A mic or other way of getting signal into the soundcard does allow some interesting educational software to be used, not just recording.  Also some interesting utilities like Scolily which can take sounds played into the computer and turn them into a written score, and some software synthesizers so that you play a note on guitar or violin or whatever and it can come out sounding like a horn or xylophone or whatever.

Your setup sounds pretty good!