You can't rebuild IHI turbos so you'll have to get a new one if it is shot. How many miles on the car? Ya have to remember that turbos are subject to extreme heat and extremely high rpm's (think 100k rpms). Depending on the mileage and severity of driving it's possible it's just dead from wearing out over time.
Mods you'd have to do I can't get to specific, but definitely a tune. If you're looking for a turbo that will simply replace the stocker and keep power levels the same, everything else should be fine. You'll just need to get re-tuned to take care of any differences in the turbo. Now if you're interested in making more power, consider an 18 or 20g setup. For that you'd need to upgraded your injectors, fuel pump, and also get tuned.
Another idea would just be looking at classifieds for used VF39's and then you just swap it and you're done.
Another item to consider since you're down there, is to get a catless uppipe. They have been known to fall apart and send crap through the turbo, killing them. You're model year is the last year to have the cat fyi. It will add a bit of power, but the main reason is to give you a good safety factor. It could have even been the cause of your turbo going out. If you pull it, check the turbine and see if the fins look really chopped up- that's the sign you sucked up the cat in the uppipe.
Hope this helps.