I built a rigger last month off the predator plans and this is what I ended up with.

http://www.rcuniverse.com/forum/m_4435355/tm.htm

I downloaded the plans off the internet, burned them on a disk, and took them to a local blueprinting shop. They cost like $1.50 a sheet! So needless to say its not going to be the last.
I did have trouble with the sponsons but after a couple of tries they turned out good. If you dont want to cut the sponsons yourself both Blew by you boats and Climate boatworks both have sponson repair kits that come with everything you need to build sponsons that will fit this rigger and are race proven shapes. The climate sponsons are all wood while the bby sponsons are plastic. They dont offer them on there website but just email them for a price.