PAP2 and PABX. How?

[callopsitte_himself]

Actually I'm "hooked" with pbxes.org.
I have a paid freephoneline and a GV. I've arranged that destinations I cannot call with FPL I can call with GV using my same handset (fixed through the outgoing routes of pbxes.org).
I know many have made themselves a home pbx with an old computer using freepbx. I'm guessing this solution might be too much of a hassle for me.

I found a cheap 3 line, 8 extensions pabx online http://www.aliexpress.com/item/Telephon ... 78374.html and I,m wondering if this could do the trick without too much trouble.

I'm using a PAP2 that I hook up to my homeline (don't really remember how but to have all my wall sockets work with my phones).

So I'm wondering if it is possible to add this pabx to my PAP2 and how (instead of using pbxes.org). Or is it rather an IP Pbx that I need?

Maybe I'd be better using an old PC and load it with the free pbx (on linux). If so how do I install all the hardware? Do I need a regular modem in the PC?