Looking for a fellow traveler to Pindul Cave

Hi, my friend and I are planning to take a tour to Pindul Cave on January 15, 2013. We're going to depart from Solo to Terminal Wonosari and we plan to use valadoo.com's service to get someone to pick us up from the terminal to Bejiharjo Village where the cave is located. The thing is that I just got informed by my friend that the tour required us 4 person(s) in the group in order to use the pick up service, so we're missing two more person(s).

Is there anyone who would be interested in joining? My friend and I wouldn't mind having either an Indonesian or a foreign company. Suggesting other method of getting from the terminal to the village would also help, but we're rather not taking rental cars since we both have limited budget and none of us is yet to obtain a driver's license.