Hi there, sorry I missed your post. (It's been a bit mad busy at my end!)
How much are you looking to spend? I'd say get the head off, go with bigger valves, 3 angle valve job and gas flowed head. Then look at the exhaust headers and fitting a sports catalyst.
Add in a fast road cam and get a remap done. That should see a nice power increase around 10-20% more bhp.
For brakes you'll need a big brake conversion kit. The Shogun brakes are pretty much the biggest IIRC in the Mitsubishi range. Try a pad upgrade first and see if this improves the braking.