Multi-ply with a stainless core is probably the most practical. In fact, the best option for most home cooks is to build a core set of multi-ply then add specialty pans as needed. I have my doubts about how valuable it is to have the conductive core come all the way up the sides on sauce pans, but that seems to be the way it's done with the really good pans.
The enamel over cast pans are very nice new, but they do stain and scratch. In terms of even, low, and/or controlled heating they're quite a bit better than cheap stainless or non-stick aluminum but not much or an improvement over good multi-ply or heavy duty aluminum.
I mostly use old fashioned Calphalon dark anodized (not non-stick!), and some plain ol' restaurant grade non-anodized aluminum as well. Unfortunately, old Calphalon isn't available anymore but there are a few well made clones and you seem interested in (at least) one of them. While it's never bothered me, some people find the dark interiors make judging colors difficult. Judging the color of rouxs, reductions, browned aromatics, and wine sauces is critical.
Plain aluminum is very common in restaurant kitchens, or it used to be. It's popularity is mostly a product of its cost -- it's not practical as an all around sauce pan because of its reactivity to "acids" like vinegar, tomato, and wines.
Were I buying new pans today, I'd buy the Vollrath commercial multi-ply -- especially sauce pans. There are less expensive and better looking options, but you just can't beat Vollrath when it comes to quality, utility and abuse resistance.
Hope this helps,