Architect / developer question. Equity stake?

[Matthew Huber]

I am an architect in New Jersey working on a 6 unit building with retail space on the first floor. We have preliminary approvals on the design and are starting the Planning board process. This is the owners first development and the project has been at a stand still for months due to the client being over seas and not around enough to push things forward. I approached the client and offered to spearhead things to get this moving along with some type of equity stake ownership to which they are interested. I have never done this before and was looking for advice and any suggestions anyone might have. Essentially I would manage the project, coordinate all the other professionals, as well as use my services as an architect providing the construction documentation / permit drawings , meetings etc as equity in the project since I would essentially be acting as the developer / architect. I am having a hard time coming up with a proposal for this and what percentage of deal would make sense to both parties. Any advice would be greatly appreciated.