Here is another link for alternative springs and combinations that that be used on the front of Toyotas. This guy has done a lot of trial and error research and his stuff is concise and well written. This link includes a huge amount of information on Toyota front ends, how they work, how to modify them, what works and what doesn't, etc. Worth checking out...

http://www.mindspring.com/~jayk3/toyota/frontaxle.htm