Need my website remade without affecting seo work with mobile apps

Hello, I own a small-mid size taxi company in Brooklyn, NY. We are hoping to become larger and get more customers through our website. Right now the website looks rather plain and the reservation system is simple and just comes to an E-mail. This causes us to sometimes miss reservations made through the website. I need a professional system where the reservation made will pop up on all computers logged in to whatever system you create for me. I need someone to redesign my taxi website. The main thing is that i don't want the seo work that has been done to be affected. Person must be willing to sign a contract guaranteeing this. I would like the reservation system to be sophisticated and use a login to system to make things easier for my regular customers. Key Points that i need -User friendly modern website -SEO work that has been done so far should not be affected -color scheme should be avatar green black and gold -freelancer responsible for all images designs and everything needed to complete the project -must be flexible and willing to work with me as i have ideas and small specific little things that need to be added along the way -mobile apps must be designed created and approved by the apple store and google play stores -reservations that come in through mobile apps should also pop up directly on dispatchers screen as well -users should be able to download the app on the apple or google play store -the user app should allow them to login, reserve a car, check their previous trips, check their points -the mobile app should be designed so that a driver can login and we can dispatch calls to drivers who are logged in on the driver login -freelancer is responsible for creating the program or backend of website where the dispatcher will login and reservations will come up as they come in -Login system where users can store pickup and drop-off addresses as they reserve cars -should be able to enable a payment system in the future -should be able to have a points system for each time they use our service and receive a discount or coupon at some point -a quick reservation system should be available on home page with a simple quick login and reserve option -users should be able to create an account using their facebook account or create a new account on the website Website and mobile apps should be open api and have an easy CMS for me to make changes on. If i decide to add more features to the website or mobile apps in the future it should be easy for any freelancer to do so. I have a few websites in mind that can help with ideas and i have software which does some of the functions i like. Please bid only if you can do ALL of the work i asked for not half or 75% of it.