RE: How to build a cheap GOOD heli.
Until you get into inverted, I don't think a swash leveler is a big deal but you can get it.
Some metric hex drivers for sure. The one that they sell that is a $8 kit where the spare drivers go into the handle (portable kit) is nice. Don't get the ones where the driver metal is black. That stuff sometimes is soft metal. Blade balancer is something you should have.