I recently did the same swap from the old interlock/wired ignition barrel/steering lock to the newer style from the UK in my 97SW (auto box) without issue. (Also did it on my 94, but that one didn't have the interlock, as its a manual box.) You can just buy the switch on he back (the round thing wih the contacts on it), or you can swap them between barrels.
In order to remove and replace them, there are two small screws on the circumference. Once removed, the switch part comes straight out. These two small screws are why its such a pain to replace the switches while the barrel is still mounted to the steering under the instrument console. The are a few good threads on here with photos that Josh (Horsey) did a couple of years ago when swapping his.
As for the 97-style interlock part, as I understand it, that interlock is basically just a solenoid that won't let you remove the key unless the auto tranny is in park. I just make sure I'm in park when shutting the car off
I'm not sure that actually does anything with the chime. My truck still makes "keys in the ignition chime" and door open with the new switch barrel, even with the new assembly.