What about the 12C67x? You can program it to your heart content to do
just what you want it to do. Only $3.18 at Digikey.
It's got 4 times 8 bit AD, and I am sure with clever programming and a
few resistors, you can have from 8 to 16+ bits.
Just an idea, as I haven't tried it.

Quentin

Wagner Lipnharski wrote:
>
> Try the Maxim's 12 serial ADCs in 8 DIP pins, they have several, single
> dual and even quad in a single package, it only requires a ref voltage
> and
> communication is via two or three wires.  Take a look at their website,
> and go to parametric search... they are from $6-$25 per piece...
> Try MAX187... $18.00 at Digikey.
>