At the speed I paint, just fitting an occasional one in now and then would put pressure on me.

That being said, it would be surprising how quickly you built up a range, just by working on a single figure occasionally, alongside your paying work.
But please... bear it in mind, the separate heads and weapons etc, a la Crooked Dice, would be ideal. Obviously I can't predict how interested other people would be though.
The series you're thinking of is Frank Darabont's '
LA Noir'... same topic and time frame though (different book). GS is a movie.