Per wikipedia only 30 to 35 were built of which 24 were bombers.
Hence this line:
The P.108B "Bombardiere" would become the dedicated workhorse and heavy bomber platform of the Regia Aeronautica.
is entirely false. It was not a dedicated workhorse or heavy bomber platform for the RA. Maybe they intended for it to be so, but it never happened.
The workhorse bombers for the RA were the SM.79-II (1350 built) and Z.1007 (660 built). It is, to me, absolutely clear that the next Italian aircraft should be either the SM.79-II to add the core Italian bomber, the C.200 to add another important fighter and use some of the 3D artwork for the C.202 or the G.55 to add an Italian MA toy.
If you want an MA bomber it really doesn't matter which nation it comes from as all sides have all units. Look into the aircraft on this list:
A-26 Invader
Do217E
H8K2 'Emily'
He177A-5 Greif
Ju188A-1
P1Y1 'Frances'
Tu-2