Once again, sounds like E-2, i.e. treaty investor. Requires a "substantial investment" which means something like $50,000+ valid for two years, can be renewed indefinitely, but as I said above, getting LPR status from E is pretty difficult, basically you have to get married to a US citizen or possibly do EB-5 later on which requires a minimum investment of $1 million usually.
For you both to get it, you both have to invest. $100,000 sounds like a lot for a restaurant.
For E there is no actual specific amount, it depends on what your business plan says. The best advice for a situation like this is to find an immigration consultant who is familiar with applying for them as they will have experience as to what the consulate will accept.
More info at:
http://toronto.usconsulate.gov/content/ ... ment=evisaE is by far the most complex non-immigrant visa, even if you find someone who already has one the advice they can give you will be minimal because their business will be different, which is why it's a good idea to find a consultant unless you're really clued up on doing financial statements and US business law.
Note that the spouse of an E-2 visa holder can get work authorization by filing I-765 - however children cannot, so if you want kids, make sure they're born in the US otherwise they will have no status when they grow up.
Steve.