You should definitely apply to that first job if having technology stacks yanked out from under you sounds annoying. It sure sounds annoying to me.
FULL DISCLOSURE: I wrote the first job description.
FULL DISCLOSURE: I wrote the first job description.
You had me at "syncretic.sausage"! Please promise me that you'll make .sausage a custom TLD someday!
Locking yourself into a technology choice is a hard decision to make, but if you're living the dream and need to attract a certain kind of person to make that possible and it makes financial sense in the short term, which is what you're probably after, then you have to go with it. Rails and Node.js are a perfect fit for a low-level technology service provider, but beyond that they lack mainstream credibility and when you're dealing with recruitment issues, which hopefully you will, it's always easier to hire someone who has versatility over a guy who just does one thing.
Good luck and I hope to checking out your work some time soon.