You'll want to be careful about discerning spacing from cog widths and spacer thicknesses, since the cogs have asymmetric machining features on the Suntour freewheels.

You'll certainly also need to use 9-speed chain, which offers the most-forgiving shifting on ALL Suntour and Shimano freewheels anyway.

I'm kind of thinking that your choice of cog sizes will affect how responsive your shifting is, and may need to be mellowed with some extra chain gap (increased b-tension) if the chain wants to overshift over your modified cog spacing.

The Campag Ergo shifters are also less controlled in terms of indexing than are STI shifters, in that Campag's Ergo indexing is forced-spring-detented in both directions, not controlled by actual ratcheting at the level of the shift spool as are Shimano's.
This means that I expect your creation to be very sensitive to both cabling quality and operator technique.

Lastly, shifters that allow shifting while off of the saddle are designed to be used with very robust, HG-style chain and sprockets, lest the rider be thrown off line by any slippage resulting from using old-tech and/or mis-matched parts. In short, this sort of conversion could be hazardous and annoying to a rider not willing to accomodate it's finicky nature.