#2 sounds like a safer / better bet to me. They're more established, they'll pay you more, you don't have doubts about their viability, and they're closer to a

#2 sounds like a safer / better bet to me. They're more established, they'll pay you more, you don't have doubts about their viability, and they're closer to actually turning your equity into something valuable. #1 sounds like you just want to build some from scratch. While I understand the appeal of that, I wouldn't make a career decision based on it.