If it's just surface rust and not anything with depth or pitting, then I highly recommend Eastwood Rust Convertor. Just brushes on, dries to a nice satin black finish.
Also give a serious look to these areas as well.
-Between the gas tank and skid plate
-rear swaybar mounts on the skid plate
-bottom edges of the doors
-firewall, back and front, especially in the area of the brake and clutch cylinders.
My oil line fix
My 100k stopped odometer fix
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.