Hifiinbau in Punto SX 60 BJ.97

Hello, so I want to install an inexpensive Hif system in my Punto rear. I was thinking about a 2- or 4-channel amplifier and 3-way boxes, or another subwoofer. The problem with the whole thing is that I am an absolute layman and have no idea of the connection possibilities 🙂 Therefore my questions: Can I connect to a 2-channel power amplifier only 2 boxes or a subwoofer, or are there three connection options (so also for a subwoofer)? Do I absolutely have to Get an MFT plate in order to be able to install two boxes in my rear shelf, or does it work with the normal shelf? Will the rear shelf with boxes or with MFT plate and boxes not be too difficult, so that I get problems with opening? Can someone recommend me a subwoofer or bass roller (no idea what the difference is) that needs as little space as possible? THX already for the answers!