Peter M, it's a mine field to be sure. Metallics can be done with Acrylics too, unless you are looking for a real metal mirror finish like Alclads. And that is generally only Airbrushed. If you just want a silver or steel finish on small parts, you can't go much wrong with the Vallejo model air metallics (even for brushing) which are water based and easy to work with. They are also a bit cheaper than Tamiya and you don't get all the nasty build up around the rim as it's in a dropper bottle.
Lacquers, I definitely recommend the water based Varnish offerings such as Vallejo and Alclad Aqua, water based will not react with much underneath as long as it's fully cured (Including decals etc). Anything solvent or alcohol based runs a risk of interactions, sometimes even with same brand/range paints, it's about the chemistry of how a Lacquer differs from a Varnish
Lacquer actually melts the layers underneath, sometime right down to the plastic, and if all goes according to plan, creates a chemically bonded single entity consisting of plastic, paint and gloss (or matt) surface. Varnish acts more like a clear paint, and should be impervious to water once cured, but may be prone to damage by alcohols or solvents depending on the chemistry of the Varnish. (It's also easier to strip off and start again if it all goes wrong)
I've actually had Tamiya spray Lacquers soften Automotive spray primers to the point you could get the well cured primer colour rub off on your hand while the lacquer was wet.
16. June, 16:40