I like this decal place. Good service
http://www.bobwhitedecals.com/
On the stiffening the road racers forum here can comment but I know there a alot of bolt on weld on frame stiffeners available. Probabaly need some real advice before you go in to those mods
Yes, true dual exhaust is a good idea for adding power. some where between 5 and 20 HP depending on other mods. Plus the opportunity to get a better sound. MAC has bolt on's for the V6