I would pick between Booth and Tepper. If you are hoping/planning to keep your job while studying, I would pick Booth - it is a very strong school with substantial resources in mid-west and Chicago. I don't feel as well about UCLA unfortunately, after getting to know some of their alums and about the admissions standards. The EMBA and FT programs will be quite a bit of a diff experience. In the EMBA, you will be among peers, and people of similar age and place in their career. With FT, you will be the old guy in the class, though it seems they are open minded to older applicants, which is great, and means you will have a small group of you 35+ year olds. FT program assumes taking time off work, getting internship (which is very helpful for career switchers), and allows some time for self reflection... I feel you have a better fit among the EMBA crowd. You can network with all of the other EMBA students who are currently also employed. You can keep your job (which you can always quit and move to Chicago if you potentially find an internship - I would talk to the Admissions/International Students office about ability to do an internship with EMBA and whether anyone has done that before - they may have to think about this one).
Visa is a good question. However, you technically do not need a J1 or any kind of a work permit to work in the US for your company back in Brazil (remotely). It is a gray land that will be probably impossible to resolve since your employer in Brazil is not in LA and did not hire you to do a job in the US. Basically it would be a hassle for the US gov, your employer, and you, and in the end it won't result into anything (unless I am missing something).
Congrats on your admits and good luck with the decision!