I started this same puzzle a year ago at:
http://www.mersenneforum.org/showthread.php?t=7051
Also in 2005 by someone else at
http://www.mersenneforum.org/showthread.php?t=4756
And a related 4-9's puzzle at:
http://www.mersenneforum.org/showthread.php?t=7060
There are several links in these posts to other web sites that solve problems with 4 of just about anything and just about any set of rules you like.