We would appreciate if you could allow us some time to get back to you on this matter.
We ask that you give us a few days in order to process your inquiry. Thank you.
ご質問ありがとうございます。
① "We would appreciate if you could allow us some time to get back to you on this matter."=「ご回答までにしばらく私たちにお時間を頂ければ幸いと存じます。」
② "We ask that you give us a few days in order to process your inquiry. Thank you."=「この案件を調査するために、数日間ほどのお時間を頂きたいと存じます。ありがとうございます。」
ご参考までに。