Compact cranks [110BCD] and square taper BB

so: the Mirage or Xenon chainset.....requires according to Geoff Butler and ribble a CT [Campag, i presume] front mech......will that work with a shimano rear mech and Shimano Ultegra bar ends?

It will work fine with a shimano front mech, they just note that for all Campag set ups you should use the CT front mech in contradistinction to the regular Campag one.

The Stronglight Impact [aka Sugino] requires a JIS bb....and the Campag one on my new frame is ISO.....are they not compatible?

You might get away with putting a crank which needs a 107mm JIS BB onto a 111mm ISO one, in theory. People who have actually measured the relevant parts with good quality instruments realise that theory is BS as far as cheap square taper fittings go, the tolerances are bigger than the supposed difference between ISO and JIS.