Thanks 'Tricky' -
A quick check of the items referenced shows that:
The Enclustra Mercury SA1 pricing starts at $385 USD and goes up from there.
HumanData has Cyclone V-based SoM boards, but are pricey (starting at $397 USD(!)):
http://www2.hdl.co.jp/en/index.php/altera-series1/cyclonev.html http://www2.hdl.co.jp/en/index.php/altera-series1/cyclonev/acm-027z-ql.html Here are other boards I have looked at
While I have found many Xilinx-based SoM boards, here are that have attractive pricing, small form factor and more than 100 GPIO user pins (LVTTL-compatible):
Numato "Saturn" board, Spartan 6, 118-145 user GPIO pins on 0.1" headers, $119-$136:
http://numato.com/saturn-spartan-6-fpga-development-board-with-ddr-sdram.html Ztex "2.01" board just barely squeaks by with 100 GPIO pins, Spartan 6, ~$109 USD:
http://www.ztex.de/usb-fpga-2/usb-fpga-2.01.e.html Myirtech "Z-Turn" Zynq/10 or /20-based board, $109-$119 USD, 96/106 user GPIO pins (we'll let the count squeak by):
http://www.myirtech.com/list.asp?id=502 Myirtech "MYC-7010/7020 CPU Module", $139-$159 USD, 100-125 user GPIO pins,
http://www.myirtech.com/list.asp?id=525 The MYIR ("Make Your Idea Real") board is the most attractive X-based board at this point since it uses the Zynq chip, with the Numato Spartan 6/45 module a previous-generation runner up.
Back in Altera-land, I found the Denx MCV-2DB module, starting at ~150 USD and up, supposedly 145 user pins:
http://www.denx-cs.de/shop/?q=mcv-2db which looks promising.
I'm trying to get Socrates II pin count, price and ordering information, but it has been frustrating trying to get info from the various web sources so far.
Thanks for the hints, and so the search continues.
Bruce