If I could be born again, I would choose the same parents.
If I could have another life, I would still want the same parents.
この場合、If I could ..., I would .... を使って次のように言うと自然で良いでしょう。
ーIf I could be born again, I would choose the same parents.
「生まれ変われるなら、同じ両親を選ぶだろう」
to be born again で「生まれ変わる」
to choose the same parents で「同じ両親を選ぶ」
ーIf I could have another life, I would still want the same parents.
「生まれ変わったとしても、同じ両親がいいな」
to have another life で「生まれ変わる」を表現することができます。
ご参考まで!