I'm going to redesign my website. Contractor or agency need to be responsive, experienced, provide high quality work. Attached more information about the project - I'd like to get estimation and quote from you. Begin your application letter with "quote".
Ideally i'd like to find a contractor who could provide some more ideas to make my website user friendly, help improve conversion and be interactive.
Do NOT provide generic cover letter - i'll read everything about you in your profile description.