Should just make it League 3 and be 2 autos and 1 play off team promoted.
All but 2 of the National League teams are fully professional these days.
I know a few players who play in the Southern League Division One ( which is one league below Weston super mare, Merthyr town etc ) and they are paying the players £350 - £400 a week, so while not professional, even thats getting close to it