Thanks to all for the replies.

I found another multiplexer, 74HC(T)4067, 16 to 1 analog. I think it is the one to go (will support 8x16=128 pots maximum!).

Darrel, in your case I suppose that you had AC signals? That's why crosstalk was important. In my case and maybe Steve's DC or low freq does not need any good crosstalk parameter. A HC series might be just fine.

Again thanks to all (and Steve for the files, I got them).

Ioannis