Nothing wrong with a modern 105 groupset for most riders IMO, more than does the job but it may give you some grief on the current bike.
Campy and Shimano are not compatible in many areas and you will hit things like the Shimano rear cassette not fitting on the campy freehub which will result in scope creep as other parts also need to be replaced...
Campy and Shimano are not compatible in many areas and you will hit things like the Shimano rear cassette not fitting on the campy freehub which will result in scope creep as other parts also need to be replaced...