When you're first starting out, its much better to outsource this stuff. I'd recommend looking at WP Engine. They have a white-label program where their system can be made to look like yours. There are others that are similar. I run my website on their site, though, and have clients I've referred to them. I'm quite happy with their performance.
Developing that kind of functionality from scratch, setting up and performing procedures to keep things patched, etc, would be extraordinarily expensive.
Get your actual business up and running first, and then, when you have a very large quantity of paying clients, pay to set up your own system. You will have enough to worry about finding clients, managing them, setting up the sites, etc. You don't want to have to worry about infrastructure stuff.
How do I know? I run a custom dev shop. If you came to me asking me to develop a system for you that would do this, I'd tell you 'no,' unless you had several hundred thousand dollars you wanted to throw at me, and you told me that you didn't care about the money.
You will find people that say, 'sure...do it yourself. its simple. Here's a list of things to do to get yourself up and running.' Don't listen to them. Their list will work just fine, until it doesn't. What happens when: your servers crash, 30 of your clients' sites get infected with malware that you can't figure out how to get rid of, a system update causes things to slow down dramatically, one of your clients' sites goes viral and your servers can't manage the load ... etc etc etc.
Developing that kind of functionality from scratch, setting up and performing procedures to keep things patched, etc, would be extraordinarily expensive.
Get your actual business up and running first, and then, when you have a very large quantity of paying clients, pay to set up your own system. You will have enough to worry about finding clients, managing them, setting up the sites, etc. You don't want to have to worry about infrastructure stuff.
How do I know? I run a custom dev shop. If you came to me asking me to develop a system for you that would do this, I'd tell you 'no,' unless you had several hundred thousand dollars you wanted to throw at me, and you told me that you didn't care about the money.
You will find people that say, 'sure...do it yourself. its simple. Here's a list of things to do to get yourself up and running.' Don't listen to them. Their list will work just fine, until it doesn't. What happens when: your servers crash, 30 of your clients' sites get infected with malware that you can't figure out how to get rid of, a system update causes things to slow down dramatically, one of your clients' sites goes viral and your servers can't manage the load ... etc etc etc.