A list of referees and judges will also be submitted with both camps agreeing on who to use, Arum said on Thursday.
Arum said the parties in Australia were eyeing a November date at the same Suncorp Stadium in Brisbane where Horn beat Pacquiao in controversial circumstances last month.
A temporary cover would be constructed at the outdoor arena to cover the ring and the first 10 rows of spectators, a precaution in case of rain, he said.
"Manny's on board, Horn's on board," Top Rank Promoter Arum said.