I run semi-slicks on my SS. Kenda Krisp 1.95", cheap stuff from local sports store (no LBS here). Do the job for the gravel and unsurfaced roads that I use it on the most. More speed than knobblies on hard surface & more trustworthy cornering.
btw: narrow tyre does not equal less contact area. More pressure equals less contact area. Often, narrow tyres have higher pressure rating, hence the smller contact area.
Wide tyres are less aerodynamic (high speed effect), for sure, but have higher volume which can lead to energy loss in the things compressing and expanding, but will also, generally, be more comfortable.