Creative Sales Letter

We're a team of 50 designer catering to publishing industry. We need nice and creative sales letter and attractive writing so the client will read and inquire about our services. Brief about us: We offer book design services, cover design services including full composition services. Do ask us if you need more information to write the sales letter. Please note the letter should be very professional as it's going to large publication house. No. of Letters : 5 Min words : 250-500 with proper heading, subjects etc. Thanks