I hope they start having more choices in the near future when it comes to milk in Japan.
この場合、次のような言い方ができますよ。
ーI hope they start having more choices in the near future when it comes to milk in Japan.
「日本で早くミルクの選択肢が増えるといいなあ」
to start having more choices で「選択肢が増える」ことを言えます。
ご参考まで!