realistically, there are very few tools needed at all to work on most bolt-on diy-type modifications for any mitsubishi...
1/4, 3/8, and 1/2" ratchets, extensions, and swivels
10, 12, 14, 17, and 21mm
-sockets
-wrenches
those are just about the only sizes you will ever encounter on the car when it comes to nuts and bolts, so basically having a set of those wrenches and sockets in 1/4" and 3/8" sockets with ratchets (1/2" drive for the 17 and 21 makes it easier for sure) along with some ratchet extensions and universal swivel joints is about all you would need for this car. only other things that are quite commonly needed:
philips and flat head screw drivers in various sizes and lengths
interior trim panel remover tool
rubber mallet/deadblow hammer
prybar assortment
wire cutters/strippers/crimpers
more specialty type stuff needed for the heavier-duty type jobs, but the basics can pretty much all be accomplished with what i've got listed here. good luck