To install any Shimano groupset you will need to get either a replacement freehub body for your current rear hub (may not exist or be difficult to source) or a new rear wheel. You can relatively easily learn if the BB is Italian or BSA by measuring over the bottom bracket shell: 70mm for Italian, 68 for BSA. I suspect BSA on that model/vintage of bike.

I'd probably try the IRD option. Another option to consider would be to fit a 48/32 crankset with the Campy 12-29 cassette. Praxis Works makes some good cranks with these things, and also FSA offers some options labeled as "Adventure" cranks. Either could work on your frame.