(mail server,web server, name server) the whole design.and find description for complete question.answer it through proper network design and diagram

Well, 

Most of the time i get upset just by the thought of writing so much trying to answer a question while i could better faster easily do that on a board drawing diagrams and stuff :)) but thats just not possible.

1) Get an IP (or a pool of IPs) registered as NS Server for your domain.

-) Your ISP might offer to register you

-) Ensure cealn, whitlisted and greeeeen IPs so your NS server reachable by users from anywhere.

2) Put (deploy) following servers in place

-) AD (Not really that necessary .... but just to be traditional)

-) Mail Server (i Would use MDaemon) that equally good if installed on Win or Lin

-) You said unlimited users (that's freaky) but it calls for a seperate  DBServer to support user profiles and credentials for your website...... so MySql, SQL, Oracle what ever it may be depending on your application specific scenario. 

-) WebServer (i would go for Apache definitly) but still, its upto what your application for your website is going to be. 

-) BIND is hell customizable, go for it but Windows DNS in2012R2 is ain't bad either but only if you can keep it secure and less vulnerable to security breachers arising everyday. This is the machine that you got those IPs registered for.

3) well, if you have AD (remember it was optional) do replicate all records on BIND from DC Machine local dns. (this may be not that necessary if you can scheme out your design .... DNS forwarders could save you from configuiring every DNS record on BIND)

4) Host records for DBServer, DC, Apache, NS itself, MDaemon.

5) Webserver: if its not a mission critical or specific application that you are building onto webserver, and its just website that you want for users with their own login accounts..... go for Drupal CMS. it gives you not only dynamic websites, but will provide you flexible permission based user accounts and content for your website.

6) find some plugins to make Drupal integellient enough that it interacts with MDaemon n DNS or even AD to carry out your website functions.

7) in most cases, you will need to script quite a few tasks on Drupal for example when you want an email account autmatically creating in MDaemon when user fill a signup form on website.

well, there is alot more to be said.

but i guess this the first step to a bigger picture.

Thank you

sorry, if i wrote something wrong.

i am TODDLER anyway :)

1)  Your browser and other software tools can use that label to find a specific computer on the Internet. Configured correctly, a domain name under your control can be pointed to WebFaction’s servers.

2)Domain names are managed by REGISTRAR. You can purchase a domain name through a registrar; the Internet Corporation for Assigned Names and Numbers (ICANN) maintains a list of accridated registrar. You may already own a domain purchased through a registrar, reseller, or previous web host. If you don’t already own a domain name or you would like to purchase additional domain names, purchase one through a registrar or reseller. At this time, WebFaction is not a registrar and does not sell domains.

3)pointing to ur domain to webfunction's server

e.g webfunction.com192.168.1.10

now just key points...

1. Log in to the control panel.
2. Click Domains / websites ‣ Websites. The > Home > Sites page loads.
3. Find the relevant website record in the list. The IP address is in the Ip column Adding a Domain to the Control Panel

4. Log in to the control panel.

5. Click Domains / websites ‣ Domains. The list of domains for your account appears.

6. Click the Add new domain button. The Domain names to add field appea

7. In the Domain names to add field, enter one or more domain names (including the TLD) separated by spaces or newlines (e.g. example.com or example.com www.example.com).

8. Click the Save button. The domain names are added to the list of domain names and a confirmation message appears.