Thanks for the update. Please let us know how the boost-converter design is coming along. In the meantime, I (and many others) will be looking forward to the "plain" ATX board :->.
BTW, for those who haven't already acquired enough S100 connectors, a cost-effective supplier (in the US, anyway) is Anchor Electronics. Catalog:
http://anchor-electronics.com/price-list.pdf
On Page 17 you'll find that for the 100-pin edgeboard connectors:
Solder-tail $3.95
Wire-wrap $6.95
Best prices that I've found *anywhere* (excepting occasionally on eBay for WW). Note that shipping is FedEx (no exceptions), so the actual cost-delivered will be higher per-item. Orders only phone-or-fax.
They are a great source for numerous hard-to-find components.