I guess thats why its called a "forum".
The 212 evolved due to the Canadian Armed Forces request.
The 214 did not evolve from the 212. It was due to the "Hot and High" issues in Iran and the UH-1/205 being hopeless there. Commonality between a 212 and 214 is about zero.
The 212 Single is basically a 205B. You can "upgrade" a 205A1 to 205B by SB but it is easier to "downgrade" a 212 by STC as most of the work is already done for you.
As to "converting" an N to civil B212 - no chance.