I need a website developed from scratch

Hello, I am looking for someone with experience in creating a website from scratch, making sure all the links work, the speed on the website is fast, all plug ins work, the cookies etc (not sure what is exactly needed) and to make sure the website doesn't crash. It is very similar to a dating site so if you had experience with that. I have the basic name for it and colours I believe would work best. I'd prefer someone in London so I could potentially meet them or be next to them once or twice to see the work and change anything if need be. I would also need some sort of guarantee if I make a website with you after a year or so any updates you'll be able to do etc.