Tough decision.
Kusturica is the best ceiling player with the most baggage and hoops to jump through to land. And we are already log jammed at the 6-7 to 6-9 wing slots. But with a self imposed minutes restriction, he is unlikely to be upset by low usage, not cause problems with current roster guys by taking their minutes or starting spots, and won't be expected to carry the team. This is the safe play and the one you have already put the most work into.
No one on Michigan's roster of note, although very talented, showed ANY interest in UK previously. Anyone worth taking would clash with guys UK already has on board. Are you benching Zoom for Cadeau if you are the UK staff? What about benching Moreno for Thiam? Bench Wilkins for McCoy? Gonna promise starter minutes to Estrella? Are any of these guys you "might" convince to come here going to be happy with limited role, going to be a team cancer, or quit on the team? Too many question marks here for me personally. I think you go for Kusturica and this is a fall back if you miss on Kusturica and the current backup plan, Hugo Ligma. There's no guarantee any of these guys will even portal yet. What kind of message do you send to the players on the roster currently if you bring in someone that will start over them (at this point in the summer).
Third option only comes available if a college head coach leaves his program to take the UM job. If an assistant, an interim internal appointee, or a currently unemployed coach (Billy D for example) takes the job, this isn't even an option. I wouldn't want to put my eggs in that basket. But at the same time, there is no clue what value players would be here if it happened because we don't know who or what or when yet. So give me Kusturica still.