What hardware do i need in order to integrate Click to Call?

Im willing to make a system where agents will be able to simple click and call costumers. After few hours of reading, its very confusing for me and i dont know what hardware would i need. Im thinking to get separate machine with Asterisk installed. Then i need PBX thing.

Can somebody explain me what hardware would i need and how to connect agents PC computers to Asterisk or PBX?

Im not looking for cloud based solutions. Simply i want to build my own system. Right now i musing analog telephone lines and all i want is to connect them somehow in order to get click to call functionality.

Btw. is it possible to get inbound call with caller id? For example if costumer call me back, wil i get popup saying that XYZ costumer is calling me?

Thanks!