Solgar has a copper chelate product containing copper glycinate. Would this be a suitable copper supplement? My 3-per-day multivitamin has at least 30mg of zinc, so around 5mg of copper should be enough? I think it may be a good idea to take the supplemental copper when I don't take vitamin C and zinc - so, possibly with lunch.

Yes, take the copper and zinc at different times.

Copper glycinate is good!