Been discussed in here a lot
On the turbo the water supply and return lines are different. The Banjo bolt in the turbo end is larger so you will need the TD-04 turbo, the banjo bolts, the copper seals and the pipes. Cost new for the extra stuff is about $100, if you'r buying a used turbo you might be able to get the parts from the yard, but often they cut them when they take the turbo off.
The ECU is different, but it will work from your LPT version. the TD-04 has a heavier turbine in it so it spins up slower. the AERO ECU takes this into consideration, the non-AREO doesn't. It also will give you the most benefit from the higher boost to have the AERO ECU, but you don't have to have it and the car will run from what I'm told.
You can also reprogram your ECU using the T7 ECU tools. never done it, but others in here have.
All in all, depends on what you'r trying to get. A CHRA for the GT17 is about $400 all in if you install it yourself and it should last at least 100K if you take care of the car. The Mitsu has a better longevity record, but if you go for a used one to get all of the right bits, will it outlast the GT17 rebuild?