As for the % to charge for these fees and how to split equity (straight split, waterfall, something else) @Omar Khan can help you more than I can. 

This is the rate of return the investor needs to achieve in order to cash to flow to the next tier of the waterfall.  

Not sure why'd you'd cross contaminate (for lack of a better phrase) between owner (equity) and GC and make milestones and waterfalls and generally make everything more complicated?

If they are already in real estate they will want double digit $, if not then 8-10 is normalIn a fund I offer a preferred return with a waterfall

I understand variables drive a large % of this (equity waterfalls, exit cap rates, etc.).  

Pooling the investors dough into one JV entity makes equity management, profit distribution (waterfall) and carried interest (what you take on the back end) a whole lot easier to calculate. 

I am looking for my first 50+ unit apartment complex to purchase in the Atlanta area in the $4m range and wanted to see an example of a (redacted :-) ) settlement statement so I see the waterfall of expenses.

A waterfall schedule for allocation may make sense. 

I am trying to get 25% of the GP's waterfall cash flows, i.e. the asset management fee, and the promote.Thanks.

Do I set up SPE for each property with benchmarks for a waterfall structure?