I would just start with known tools (sounds like you like rails, so use rails), with the caveat being that you should keep SEO in mind. However, if you're using rails on the backend to render everything, that should not be a problem.

Yes, rails consumes more resources than other technologies. But if you're starting from scratch that doesn't matter. Many successful companies (worth billions) started on things like Django, Rails, etc and then later moved to other tech when it was clear it wasn't worth the cost. But not before then.

If something isn't scaling, fix it later and optimize for fast shipping