We have been in touch with many US immigration attorney's. The main options are:
EB-5- relatively slow and very expensive.
E-2- Cheaper but not an immigrant Visa. 3 year and must be renewed based on business performance. Still need to figure out immigrant visa options.
EB-2 NIW- Cheaper and faster than EB-5. Has education requirement and must propose activities (usually a business) that is in the "national Interest".