KOK5CY
To answer your original question, yes any scanner that can do Phase 1 will work just fine on OKWIN and the Miami Tower.
Phase 1 Scanners
Pro-197
GRE PSR-600
RS Pro-652
Whistler 1065 which is what I am using here in Tulsa.
BCT 996
etc.
Everyone is just saying that if you want to spend a little more money and get a Phase 2 scanner then my all means do so. As for the current state of the new system any Phase 1 scanner will work just fine. Just make sure you have a really good antenna. Remember with digital it's all or nothing. Since you will be monitoring a single site system P25 distortion should not be a problem for you.
I vote for the PSR-600, RS Pro-197, RS Pro-652, or the Whistler 1065. All 4 are identical as well as easier to program and less money. If the state does upgrade to Phase 2 in the future than yes you will will need to get a scanner that will scan Phase 2. Hope this helps.