A bro's situation:

I'm currently assigned OCONUS and I'm PCS'ing to another OCONUS location. The current location is command sponsored (Aviano), the other is remote (Korea). If I want to maximize my leave, what types can I put together to get the most leave before spending a year away from my family?

Maybe he can get 10 days of permissive for house hunting CONUS wherever his family is going to stay for the year?  I bet he could argue that point since it's unreasonable to expect him to move his family to the US and not take time to find a place.  Don't have the AFI/JTR in front of me, but COT leave is another option, though he may want to save that for a midtour.

Recruiters Assistance might be another...I used mine as a 2 LT not sure about doing it as a Capt/Maj type

Recruiter's assistance has to be approved by your SQ/CC (I also did this as a casual 2 LT) - I imagine it's low probability his Aviano SQ/CC is going to approve this right before his PCS (and if he did, that still means your bro would have to come back to Aviano after leave to out process).  How much leave does he have in the bank right now?  He can take a ton of that if he wants, but I wouldn't burn it all personally, he's going to want some leave to use in Korea.