Juventus becomes the best club for him next season. Lukaku have two best options for now.
1 Juventus
2 Saudi clubs
I don't see a better choice than those. I hope lukaku will able to decide it as soon as possible.
Lukaku have rejected with all interested from Saudi Clubs and seems he won't play there any more right now although has chance for few years later depend on how excited salary accepted. Last option for Lukaku between returning back to Chelsea or join with Juventus next season but need waiting done deal transfer fees with Chelsea. Its not easy for getting done deal about transfer fees after Inter Milan withdrew for signing Lukaku after second proposal with 35 million euro rejected by Chelsea.
Juventus is bigger teams and Lukaku have been adapted well with Serie A competition, its not difficult for adapting again for Lukaku if join with Inter Milan rival teams next season because regular position is most important for Lukaku than returning back to Chelsea where difficult to be main player under Pochettino.
There is little possibility that Inter milan will try to increase the amount of the offer because Lukaku for Inter milan is one of the players who can be relied upon and it has been proven that when he was at Inter milan, Lukaku was very consistent in every game.
Even though Chelsea turned down their Inter milan offer because it might only be a small amount but if Inter increased the amount quickly Chelsea would agree.
I'm not sure if Juventus offered a high price and Chelsea agreed but if Lukaku refuses then surely this transfer can't be done.