Need some advise
The first thing I'd say is that it is very important to have an idea of exactly what you intend to do before you start buying up speedlights. They have their uses, but there are limits to what they will do. Your lighting should be serving a craft that you've developed, a craft that you know well enough to know which tools are the right ones for it.
For example, how much power does your technique require? Do you need portable power? How much, how many flashes, and at what refresh rate? Do you really need TTL?
A pair of Flashpoint II monolights at 150 W/s each can sometimes be a good start where you need best value for the money. A pair of those with umbrellas and stands and a couple of modifiers should only cost you $300. The lights are solid and reliable, and you're not that far from NY it seems.
If you're buying into TTL flashes, then you should be sure that the 35 W/s you will get from them is going to be good enough for the job. You'll get a certain number of flashes on a charge, and you won't be able to shoot more than a certain number of flashes at a time without running into thermal shutdown. I would never use the Yongnuo's professionally. A real speedlight setup is an expensive habit useful for quite specific purposes.