EB2 Business or E2 Visa?

Hello, My sister and her family are British citizen and would like to move to US, possibly on business visa. I have filed a F4 for them but it will probably take another 5-6 years to open up. So meanwhile i was wondering if there is any options for them to immigrate/move to US and convert their status once F4 opens up. They have been doing business (convenient stores) in UK for past 15 years. So is it better to do EB2 or E2 for them? I am not sure if they are eligible for EB2? As none have bachelor degree. She has two kids who are in school. Any help would be appreciated. I am not sure if this question belongs here or not. Any group you can recommend me to look into, that would be great. Thank you! #workvisa