I'm slowly becoming convinced that AVR chips may be preferable to PIC chips, especially if you are going to use a high-level language like C.
The EDTP Easy Ethernet AVR board has an ATmega16 AVR risc microcontroller with 8 channels of 10-bit A/D. It looks like you only get access to port A (8 pins) and port C (8 pins). Port A is the A/D port, but the Easy Ethernet AVR says there is a 4HCT573 Octal Transparent Latch on port A. I'll have to ask them if they can do analog input on Port A, or else is it a non-starter. The price is OK ($64 kit, $84 assembled).
There also is the Ethernut Board that has an ATmega128 microcontroller. The Ethernut has 20 I/O pins (8 of them A/D). But the price is a little steaper, $138.