pouring over each counties website
This is the only way you will find out if what you want to do is possible unless you get a paralegal or lawyer on retainer to do it for you.
You will also need to come up with some SIZABLE capital investment. Including money for monthly leasing of a space. Typically you will want something with HIGH ceilings and a capable HVAC system, updated electrical and municipal water connection. From there you will need either get licanced or permitting to install and operate equipment. Most States that are legal require Indoor or sight unseen operations. Most states DO NOT allow for property loss insurance underwriting for grow operation business. You will be required to submit to fire martial inspections and be up to date on the local fire code.
Good luck getting a loan for start up.
You most likely will need to get private investment. There are a number of publicly traded "canna" infrastructure businesses. Many of which I have already invested in. Canada is about to explode on the publicly traded business market.. These would be your best bet for acquiring funding or venture capital start-up.
Oregon and Colorado are pretty much closed off to outsiders, Good luck navigating California laws and permitting requirements. Nevada would probably be your best best. Although, there are a number of other States that will become full legal soon. As soon as full legal at federal level, get ready for HUGH stock market booms.
Everyone is waiting.
EDIT: I am not trying to be down on your Idea, at all.