Take a look at this before you decide:
It sounds like full-autos are what you are into. The only way to build a collection that you can keep in the present day is to become very wealthy.
Dealers and manufacturers can build a collection of post 86 arms at a fraction of the cost. However they own them through their business. When the business is gone, so are the guns. The ATF will not issue the SOT unless you are in the business of selling or manufacturing Title II firearms.