Dear Sir:
Thank you very much for your interesting offer; have a polite wording has been always the great difference which makes documents something not only functional, but also aesthetical and gratifying.
If I could read a document similar to the desired result (and, of course, if you'd note the essential factors which are to be kept in mind) I'm sure we'll get those documents you desire from the very first one.
You can have full confidence that, if we could agree, your project will be studied with the utmost detail and carried out with earnest professionalism.
Best wishes
Carlos de los Rios