If you're willing to diy your own bracket you can save additional cash by getting a standard furnace humidifier valve. They're about $10 or so & should be available at most reno box stores.
As far as JG fittings & bulkheads, if you live in BC, Andrew Sheret is a good source, they have most of them & although they cost a tad more than you might find on line, they're local & a component in hand is sometimes better than waiting for the mailperson.
Here's a pic of the valve I'm talking about, I think it's a "Wait" brand. 10 bucks & a diy bracket or close to 40 for the fancy one you linked to with the bracket included:
