I’ve used a K&M Tri Level Point Light source for years. It has a 3” filter holder, but I’ve never tried it with VC paper. The light’s intensity can be varied. Point light sources are generally considered to produce the sharpest prints, and the illumination is even. However, any flaw in or crud on the contact frame’s glass really shows in the print. Some people don’t like it for that reason. (I know a very well known photographer who won’t make contacts; he uses an 8x10 enlarger with a glassless carrier to make 8x10 prints from an 8x10 neg. --- each to his own I guess.)

The K&M occasionally shows up on eBay in the $150 -225 range. The company, K&M Manufacturing Co., Inc., went out of business. The lights are getting harder to find. This place looks like the have some:

http://www.interlight.biz/itemno.int...POINT%20SOURCE

Also, you’ll need a voltage regulator and timer.

Or as Ian suggested, you could make or have a local shop make something for you.