Negotiating Carry + Equity for First Time Fund?

I am in a unique position to potentially be the second man in a private equity fund (targeting $300 - $500 million for Fund I) that a partner at my firm is looking to spin out on his own. I am currently a VP (7 - 10 years out of undergrad) and have spent my entire career covering the targeted strategy (think niche, but scalable commercial real estate asset class). We are in the early stages of securing an anchor investor (leaning on partner's relationships while I create all the materials and advise on structuring). 

The investment team will be relatively lean (likely one other originating partner, an associate, and some back office support) and I will be leading all underwriting and heavily involved in strategy creation, pipeline, etc. If relevant for comps, we are currently based in NYC but may set up shop in FL (partner's preference).

 Can anyone share advice or comps on this situation? I want to know realistically how much carry and management company equity I can push for (especially before things get too baked with fundraising) and how I should approach it.