I want to make control like this:

where I’ll be able to add/remove/edit parameters of my selected object.
It is terrible to edit object, with a lot of parameters(including enums, other class objects, arrays of variable types) in the standard Inspector view.
Any concrete ides?
I am very sad I get 403 forbidden for whatever you have embedded, but Tim's answer is still very useful for me trying to use List is a custom editor!
– ptpaterson