There are some western customers wearing T-shirts with Chinese characters on them.
Some of the foreign customers have T-shirts with Japanese Kanji on them.
ーThere are some western customers wearing T-shirts with Chinese characters on them.
「漢字の書かれたTシャツを着た欧米人の客がいく人かいる」
T-shirts with Chinese characters on them で「漢字が書かれたTシャツ」
ーSome of the foreign customers have T-shirts with Japanese Kanji on them.
「外国人客の中には漢字が書かれたTシャツを着ている人がいる」
T-shirts with Japanese Kanji on them で「漢字が書かれたTシャツ」
ご参考まで！
Some foreign tourists wear T-shirts with kanji on them.
Some foreign tourists wear T-shirts with kanji on them.
Some international visitors wear T-shirts with Japanese characters on them.
You sometimes see tourists wearing kanji T-shirts.
「外国人客の中には〜がいる」は、英語では Some + 複数形 で言うのが自然です。
Some foreign tourists… で「外国人客の中には（そういう人も）いる」という一部にいるニュアンスになります。
カナダ 
アメリカ合衆国 
