Real copper is a joy to cook with. that said the French and Belgian companies produce great stuff: Mauviel, Bourgeat, Falk. (In fact Falk produces the bi-metal the others use) These are 2.5mmmsolid red copper with a super thin stainless lining. Both Mauviel and Bourgeat also produce the tinned lined as well.
If you want to try one, go to the Falk Culinair web site and order the try me piece. It has a reduced price and will get you hooked!
If you become serious with copper you will soon learn its fine properties and the tinned will seem a good option. THese companies use a heavy tin lining, hand wiped so it's thick.
Also investigate Hammersmith in NYC and Lara Copper of Tasmania. Fine pieces, great prices.
There is much good Italian copper as well, Rufoni and Puppieni. This tends to be a bit thinner and is tin plated, a thinner coating.
The other copper pans out there are not much by comparison. Calpholon is a mere coating on aluminum, not much more than Revereware. The AllClad is better but for the same price you can get the real thing!!!
BTW, real copper is easy to clean and keep polished. THose coated pans are harder to keep up.