Why not just try making your own?
Unless they're hiding something, there are only 5 ingredients (other than preservatives) in Huy Fong Sriracha -- chilli (ripe red jalapenos), sugar, salt, garlic and vinegar.
There are receipes on the Net for how to make the sauce. And, there's actually a documentary about how Huy Fong makes its sriracha out there. I'll try to find it and post a link to it here if I do.
Can't say how close it tastes to Huy Fong's but the following receipe includes a fermentation process which is required if you want to make an authentic version of sriracha sauce.
I'd eliminate the serranos from the receipe because I don't think the Huy Fong version uses them and I'd just use plain white sugar (instead of brown sugar for the same reason) but otherwise this receipe has all of the same ingredients that the Huy Fong version does. It's just a quesstion of ratios.
See:
How To Make Homemade Sriracha Sauce.
It takes me years to use up a bottle of Huy Fong Sriracha sauce. So long, it starts to turn brown. So, I'm not worried about running out of what I've got but I know how popular it is. I even saw a bottle of the stuff sitting on a window sill in Rick Ness' kitchen/meeting trailer on an episode of "Gold Rush."
LOL!
I also know that there are some condiments (like Best Food aka Hellman's mayo) for which there are no substitutes.
So, here's hoping that you either find a bottle of the stuff still sitting on a shelf for sale somewhere or make something close to what Huy Fong's stuff tastes like.
Goodl luck!!!
PS: If you're going to try to make some, you're biggest problem probably will be finding any ripe red jalapenos because if Huy Fong can't buy enough of them from its dedicated growers, I don't know where else you'd get them but, if you're really desperate, you could try growing them in your garden.
The only jalapenos I've ever seen in the grocery store are the green ones, which obviously are NOT the ones that what you want unless you want to make green sriracha.
