Personally I would prefer an 18 team league. A 16 team league would lead to 8 less games a season than currently i.e 4 home games. The current SPL clubs would lose money on these 4 less games as well as having to share to TV money and also play the old firm once less at home per season. All this loss in revenue would only increase the chance of the division being expanded. The 18 team league would at least offer 2 additional home games that the 16 team one would not.
Also The 18 team league wouldn't be that much worse quality than the 16 teams. As it stands currently (assuming teams that needed to would improve stadia and install undersoil heating) the teams that would be promoted would be: ICT, County, Dundee, Partick, QOS & Dunfermline all of which are of an equal standard.
What would you do to the lower leagues if this expansion was confirmed?