[ASK]How to make Dial-in server with pre/post-paid system?

RouterOS General
1

Now, my MT working well. since i can use ARP feature.

Now, i want my MT box to be a dial-in server with pre/post paid feature.
What Hardware and software (3rd party?) that i can use?
what the best system for dial-in client ? is it DHCP or another?

may be, for a while i reserved about 50 IPs for client. is there i need a IP POOL ???

thanks alot