The P.108 was built in too few examples to be added in the game anytime soon... and only the prototype of the P.108A was produced. Btw, it was produced in here, where I live.
Agreed, you're talking about <50 aircraft which had limited success. Most raids with a few AC they lost 1/3 of the craft. Apparently the engine nacelle guns did nothing for it.
The Axis had some very fine bombers which were used across several fronts and in a multitue of roles, model those first. Here's betting we see an He-111 or Do-217 as the next Axis Buff.