Ask HN: Advice on vesting equity for new partners needed

A bit of background - I couldn't find a technical co-founder so I set about building my product myself and now have it in a really good stage for on-boarding customers. I don't have the time to do both building the product and selling so have met another party who are keen to get involved

To sum them up, they have connections, potentially funding and a moderate amount of influence in the industry which is exponentially more than I have and they also want to build something similar but don't have the technical capability to build something as good.

I think they are the right fit and we need to discuss terms - any advice on where to start and how to negotiate? My current thoughts on the matter are:

- not giving them more than 49% - vesting equity based on performance - happy to split all profits equally

Any advice on making this mutually beneficial but protecting myself in the short and long term would be appreciated.

Cheers