Campagnolo 7 and 8 have the same spacing as Shimano 7.
Why not use Campagnolo 8 speed Ergos. They are better made than Shimano shifters as well.
but if his current wheels have campag 9 speed cassette, then the splining arrangement on campag 8 speed is totally different
True, but with a Shimano wheel you simply run a 7 speed cassette, and Campag 8 mech and shifter.
If it's a Campag 9 wheel you run an 8 speed cassette made from 9 speed cogs and 8 speed spacers. I absolutely agree that the worst thing to do is fit 8 speed cogs onto a 9 speed Campag hub - it fits but chews up the freehub body.
Ride it or milk it!