"Well my question is how much experience do you have of managing projects and developers?"

Managing developers across various countries is exactly what I do best in the Free Software community... but I know their talents very well because most of their prior work is openly available for review and audit, and can task them where they best fit. That side of the PM is no problem.

Not knowing where to start, what developers are good/bad, and how to break this up (in terms of cost and deadlines) is my blocker at the moment. Can a good coder do it in a weekend, and not follow my guidelines? Sure. Can a "poor" coder do it exactly how I describe, but take a month longer? Sure.

I need to find that balance, and rather quickly unfortunately. I'm breaking up the features and the technologies that are required over the next couple of weeks, so I should have a better idea of what is required by then.

Yeah, but as I see that is not the only problem. As I see it you are trying to reach perfection immediatly. The trick here narrow the scope a little and what is the absolute requirements for success and what requirements are for perfection. You are looking into this problem with "We need to do this fast, there should be no bugs and it should also be easy to make faster(or keep performance) by adding X! oooh did I mention that it should be easy to maintain? Because bugs will occur, it does not always work faster(or keep performance) when you add X and we should also be ready to add feature Y within the deadline because we missed it when we started."

IMHO you need to focus on people that can produce maintainable code first, because out of that the individiuals in the team can derive high-quality and scalable code.

Also you can't do anything about the quality of the code if you don't know where quality lacks and you can't do anything to the scalability and performance of the code if you don't know where these issues are. And you'll have no chance of fixing them if the maintainability of the code lacks.