Easiest is to use 5ghz for distribution and 2.4ghz for access.
If you are planning for public access wifi, use a hub and spoke design over a linear design. This will save you a huge amount of issues but at the cost of rf bandwidth. If you can, build a mpls mesh and spoke off that for redundancy and bandwidth capacity.
Your data center should have a good enterprise router (cisco 2900 series) with at least 8GB ram, at least two servers with 32gb ram and two 10TB hdds in mirror. Using something like citrix xenserver, you create two dns servers, two log servers and you can place your controller software on a vm (most can be on a vm with a little tweaking). The idea of two dns and two syslog servers is so that you can maintain records by placing those vms on a home server (where they boot and store their hard disk image). If you do this right you can also host a chilli-spot server for public pay-per-use wifi.
Since you plan to sell wifi subscriptions, I highly suggest that you run a radius server with eap-ttls setup and use a vlan setup to point users to a walled garden if they are not subscribed. This simplifies the wifi encryption part as the encryption is device to headend not device to wifi ap. This also allows you to prevent service theft as rouge aps can not get by the firewall (in the cisco 2900 router) without proper authorization.
You dont need to host your own ntp server, but since the cisco router can, it will reduce unnecessary traffic if you do as all of your network devices can sync to your router which in turn can sync to several good ntp servers.
There is no one way to build these networks, but all isp networks share a fundamental number of services and basic operation principle