Attached to this letter is ... は 良く使えるフレーズ。 また、providing ... とか provided ... という言い回しは 条件を付記する書き方として 良く使われます。 Please be advised ... は 定型で 以下の事をお伝えします という意味のフォーマルな表現方法です。さらに provide us with という書き方も覚えておくと便利でしょう。Should ... といった書き方は フォーマルな定型のスタイルで非常に良く使われます。（例） Should you have any questions, please contact us. なお、発注書等に添付される スタンダードな約款 即ち 契約条件は 通常 general terms and conditions という言い方をします。
Attached to this letter is an overview of items and services which we are interested in purchasing from your firm, roviding your terms and conditions are favorable, and your prices are competitive. Please be advised, however, as the attached overview is only an informed guess as to our needs, it should not be considered as anything more than a brief description of our requirements.
Please provide us with your price list together with your terms and conditions of sale, any applicable discounts, deliveries and relevant sales and corporate policies. Should the information you provide be acceptable and competitive, you can look forward to our first order within thirty (30) days.
Thank you for your assistance in advance. We have also enclosed our procurement general terms and conditions for your review.Sincerely,