Help with Hardware selection

Good afternoon,

My company is looking at upgrading our PBX-PSTN (Panavision v1.1[Which is admin locked and no access]) to a IP solution using FreePBX on Ubuntu 14.04 LTS(server). I have posted on FreePBX to try to narrow down my required hardware, and seem to be directed to wiki’s which do not clearly inform me of what exactly my needs are. I have found an example to work off of but even it is not clear exactly how they are setting it up. Our requirements are below any help would be greatly appreciated.

Single building setup.
We need 32 phone lines minimum but availability to add more a big +
2 fax machines
15 concurrent calls at any given time and that’s probably a bit high probably no more than 8 at any given moment up to 15 for very high use moments.
We currently have 1 main receptionist as our transfer and 1 separate person as fallback if other is out to lunch or busy.(Prefer to use receptionist in FreePBX for this and 1 fallback if operator assistance is required.)
We will need conference capability.

Most of the hardware lists I found had multiple switches and servers (it was a medium buisness build 30+ phone using 3-24 port cisco switches etc) I just need a Nice detailed solution or diagram and hardware list, to start getting pricing and propose it to my employer for acceptance. I have already setup FreePBX on Ubuntu 14.04 Server, so I guess I would need a telephony card for this or would a VoIP Gateway still be a viable solution?

Will someone, more knowledgeable than pointing me at wiki’s that do not help, please help.

James Hinson