Downtube shifters to ergo shifters? Possible?

Are your present downtube shifters indexed? If so, then how many speeds? You'll need to try and find Ergoshifters with the same number of speeds. Shimano's are indexed front and rear but Campag only indexed the rear, the front is just a rachet so it doesn't matter.

So does this mean the other shifter doesn't matter at all? I have a 24 speed campy set up, so I would need an indexed 8 speed, but will all 8 speed sets work with either a double or triple on the front, as not indexed?

Cheers