Recently I had to choose a 12 bit serial A/D to hook up to a PIC16C84.
I searched at Maxim and received free samples of Max186. But it is
really too expansive! I searched for another one and found the one I am
using now: 3 times cheaper in quantities, 12 bits serial, about 2 1/2$.
It is TLC2543 from TI. A good choice. I have got code for it too.
By the way, it's a dil18 (also SMD parts) and has 11 mux analog inputs
David