Is this a good idea?

You're not going to need to swap in a new rear end I doubt. The 7.7" will hold up just fine in a 2.3 turbo application. Not really much reason to swap up to an 8.8" in my opinion, but many have still done this swap. If I were you I'd be worried about the A4LD. They have a tough enough time holding up in 88hp n/a 2.3's. I'd assume that using it only as a temporary application would work out, but you would definitely need to do a t-5 swap in the near future.

If your thinking of modifying a naturally aspirated 2.3 into a turbo ready motor then you will not necessarily need a stronger bottom end, but you will need forged pistons, oil feed return line, VAM, 35lb. injectors and an la3 computer from a turbocoupe. Stock bottom end will hold up though.

There are many things you can do to upgrade power in these 2.3 turbo engines. Just run a search on this forum. Good luck and let us know how it goes.

The big reason people switch to a 5.0 8.8" rear is so that it can be converted to 5-lug and use some nice big brakes. Also, there are better differentials available for the Ford 8.8" rear. Plus, it IS truly stronger than a 7.5" in the end.

For oiling the turbo, you'll have to tap the oil pan, unless you find a block from a turbo 2.3 car. The blocks are basically the same, otherwise. It's simply the rotating assembly that is different (stronger pistons). For more insurance, I would suggest buying some stronger connecting rods. Those are actually the "weak point" in the 2.3 block. Of course, a whole new bottom end would never hurt. Just make sure to keep the compression low, like 8:1 or so.

There are several different computers that will work with the VAM (vane air meter). I would recommend picking up the large version of the VAM from a Thunderbird Turbocoupe. More airflow = more power, after all. Don't forget to grab the "brown-top" 35lb injectors. The computers that are compatible (and easy to find) are the LA2 and LA3. Automatic transmission computers are the LB2 and LB3, and apparently they have slightly more aggressive fuel and timing curves. I believe that there is more to the wiring modification, though.

Other than that, James has all the bases covered.