Commision Based Web Design & Development Sales Letter

I am looking for someone who has a talent for selling, I am looking for a sales letter template I can send off to companies who have a online stores but dont have a professional look to them. For example, I was shopping for some golf accesories for my fathers birthday. Came across a site which had what I needed very cheap. Unfortunately the website was one single page, All products they sold were listed on this page in a 4 coloum format. Product, 1 sentence description, price and add to cart. When you click add to cart it took you to paypal, there was no shopping cart, couldnt add things in quantity, if you want 4 golf balls you had to buy them four times, going back to site, adding to cart, going to paypal, going back to site again and again, for every item you wanted. I have come across a few websites like this and want to email them a letter offering my website design and develpment services to them. Including some snazzy things that could be added to their site or how it could work like: - New Stylish Website layout running on an ecommerce system. - Cleaner shaping carts, Wish list which can sharable and more options for online check out. Gateways such as Paypal, Visa Debits, Credit Cards, Google pay. All of which would still enter your companies account as you wish. - Online Gift Vouchers, Promo codes, - Shop view of categories like Golf balls, Gold clubs, sets, Package deals, accesories, - Filter by sizes, price, colours - ON Sale - Deals - Featured Products - Customers can have login's to the site or guest check out option, They could always come back login and have all their details stored, See their past orders, amend their payment details, amend their address, contact details. This would also help you in the event you need to contact the customer, You can simply go to admin area of the site and find the customer details. In the admin, You see the orders as (The website will also email you all orders, customer details too) You can update it to say the order has been accepted, processed and shipped to help the customer keep updated, The customer would also be able to recieve emails of all this. Basically I want to sell this! But I want commission of their online sales. So a letter stating this which can be editted as I needed in future, But explains unlike most web developers I work on a Commision Based Web Design & Development to make it finacially easier for small companies. (I dont know if to put this but I am looking for 20% of sales), I will also Maintain and Host the website. I will even offer to do their stock control on the website (Adding, deleting, editting products) and Updating orders. Maybe add in the letter, Please see a demonstration of how your website could look! (make sure this states, Colours, Themes, fonts can change to customer satisfaction.) Then I will make some mock up designs of things like Shopping carts, Shop pages, Admin Pages and attach to the letters. So I need a strong reusable letter please. Thanks guys!