Learn English – Is this correct way of replying with available dates for an interview

Depending on the size of the vendor, your assumption may not be entirely warranted. If there are several people who may potentially receive the email at the distributor (as may happen with a shared departmental mailbox) the person who receives your email may not be aware of all the facts.

Accordingly, it may be wise to refer to the previous email at the beginning of your email (..."per the email from Mr. Customer sent yesterday regarding WidgetCo Widgets") and reiterate any key facts that you need to rely upon to make your point (..."we require, as stated previously, forty-two Widgets within a week").

By referring unambiguously to the email at the beginning, you can ensure that the person who receives your email will be reminded (if they had forgotten); will research (if they are a different person who did not initially receive the other email); or will delegate to the appropriate person (if someone else has the responsibility for this transaction).

Even if it is the same person, the phrasing mentioned above should be usable; it never hurts to ensure that your intentions are clear.

Good luck!

What you come up with is polite enough. Another option is something along the lines of,

I hope to move forward on this project next week. Please send the requested documentation by Friday; if that is not possible, please let me know when I can expect to receive the documentation.

It's a little more pointed but gives a deadline (useful) while acknowledging that their timescale may not be the same as yours (polite).