how about this bitflyer? whether you will use those who have plans for bitcoin gold
A chain split (“split”) related to Bitcoin Gold (BTG) is scheduled to occur on October 25th. Our response to the chain split is as follows.1
・We will credit you with an amount of BTG corresponding to the amount of Bitcoin (BTC) in your bitFlyer account prior to the split. 2 If the BTG split is deemed by bitFlyer to be permanent and secure in regards to customer assets, you will be able to own both BTC and BTG in your bitFlyer account.
・Services allowing users to buy, sell, deposit, and send BTG are planned for release.
・No suspension of service is scheduled around the split. All bitFlyer services will continue running as usual.
I think its a japanese exchange although the texts are not in japanese but they are only accepting japanese yen, furthermore i sense a lot of uncertainty in their statement above^, in short your BTG's might get hold off for some various reasons. In the first fork a lot of exchanges/wallets made it seem that they'll credit their users BCH asap but they did not.
You can view the list of exchanges and wallets for BTG on their official site
https://btcgpu.org/ although there's a bunch of exchanges I've never heard of so be careful if you're planning on storing your BTC's there before the fork. Still go for security