Campagnolo ergo shifters on older bike

One other thing to consider - apparently older chainrings rub a bit with narrower chains so you might want to test that. It's almost looking like it'd be cheapest just to buy a whole new gruppo.

+1
Your gonna need at least new levers, cassette, rear mech, chain, and cables.

New chain rings would be nice as you're changing the chain and cassette.
A new BB, is always welcome.
It ould seem silly at this point not to change the front mech.

A 2009 veloce groupset can be picked up for £340.
http://www.merlincycles.co.uk/shimano-groupsets/campagnolo-shimano-and-sram-groupsets/2009-campagnolo-veloce-groupset.html

If it were me I'd either go all out and buy a new grouppo, or do a cheapo work around like....

http://www.paulcomp.com/rdthumbie.html