you can find the pen type lasers on ebay, really reasonable. Make sure you can turn it on/off...otherwise you have to tape the button down to keep it on...It works ok that way...you just have to unscrew the light to turn it off (like you would unscrew a flashlight to replace the battery).
http://cgi.ebay.com/New-Powerful-Red...item3cab148a25
Above is an example of the one I bought to go with an older longarm machine. I had to come up with a device to attach it to the longarm, and taped the on/off switch down. Lasts a long time (still works 2 years later).