Perhap it all depends on the range of projects that you want to build.
There are two facets to paper model design.
There's the set of flat 2D shapes that will be cut out, folded and/or rolled and then stuck together to form the 3D shape of the model.
Then there's the matter of the graphics to be applied to those shapes to make it look the way you want.
No one whose taken the trouble to look at the images of your Soldier Settlement Cottage (
Soldier Settlement Cottage, Australia ) can have
any doubt about your first rate ability to handle the graphics part in Photoshop.
If as I suspect you are primarily wanting buildings, perhaps Sketchup and it's unfolding add on, might be a good (free) way to go.
I looked at it once a while back and it seemed to quite like doing buildings. Learn how to knock off simple structures in 3D in order to derive the
2D shapes you need and you might well be on your way.