Here is a Honeywell universal gas valve that would appear to work just as well.
- controlled by 24VAC
- takes a common thermocouple
- has an outlet for the pilot light
- 1/2" x 1/2" inlet/ outlet.
- 130,000 BTU
$69 with a 24 inch thermocouple
Honeywell product web page. The installation guide is at the bottom.
Applicable related documents
The difference between the 8500 and the 9500 you listed is that the 9500 is capable of lighting its own pilot light. ie Direct Hot Surface Ignition.
The 8500 works with a standing pilot light.
I'd rather manual light mine. Less to go wrong. The pilot assembly for the 9500 is also more expensive.
I'll need a 24VAC transformer and some relays to control it from the computer, but I would have needed that with any valve.