Yes, there is a 747 base in MIA. You owe the company 17 days a month. It can be all together or broken up. MIA flying tends to be to South America so most of the trips are shorter but scheduling will send you where they need you.

One of the F/Os that just flew me Dover to Hahn is MIA based and just off first year pay. The latest bid shows new hires going HSV and ANC.