Hi,
I have read yours requirements and clearly understand point for developing new site, installation theme and make some changes just like changes text and content.
I have very good experience in developing and customization of WordPress websites. have experience in working on lot's of free and paid theme like Avada, Divi, X theme, Storefront, Genesis Framework and much more.
I am full time freelancer web developer having 4+ experience in WordPress theme customization & developing and Plugin customization & developing, also have good knowledge of Magento, PHP and Codeigniter. so am pretty confident that i will be develop you site as per milestone.
I can assure you that if you work with me once, you will always work with me for these kind of projects.
Thank you for taking time reviewing the proposal letter.