I like the skewer idea. Probably closer to scale too. What are the pros and cons of styrene vs cardstock - it seems like styrene might be harder to paint but less likely to warp?
While some fine models were and have been buillt using cardstock, after decades of layout visits and tours I can say you can almost always spot an “old” cardstock model. The effects of humidity are obviously one thing but also the adhesives used with cardstock seem to give out over time. And from an ease of construction standpoint, nothing can beat the “score and snap” capability of styrene.
I’m also in favour for styrene, and you can make the support posts, depending on their diameter, using either Evergreen styrene rod or styrene tubing. Styrene-to-styrene joints tend to be stronger than styrene-to-wood.
If you need square support posts, you could use 4"x4", 6"x6", etc. strip styrene, but Evergreen also offers square and rectangular tubing, along with structural steel shapes (H- columns, I-beams, etc.) also in a variety of sizes.
I used H-columns to support my scratchbuilt umbrella sheds for the station in Dunnville, and each column includes a downspout, made from styrene rod…
I would stick with the same material to simplify the use of adhesive(s).
Styrene and plastics tend to use solvents that don’t work on wood.
Wood tends to work better with carpenters- -white- -glue.
Cyanoacrylate (CA) glue [Super Glue®] can work with both.
Styrene is available in a myriad of architectural shapes and sizes.
Different types and sizes of wood for modeling tend to be cheaper.
If going the wood route I recommend Basswood over Balsa.
The lightweight advantage of Balsawood is not necessarily a plus when building structures as opposed to things that fly.
If the original structure was made of metal, to most accurately represent the same structure, styrene is a better choice. Especially if the roofing material is corrugated.
However, if “just good enough” (nothing wrong with that) is your goal then the ease of working with wood is a good choice.
There is no right or wrong to your solution.
It’s a matter of compromise- -which all modelers face at some point.
If you go to a hardware store, look at pre-printed signs like Beware of the Dog or Keep out. It’s a cheap source of flat styrene, since you’re going to paint it anyway. Aluminum flash is another material you might use for the roof, although styrene is probably easier to work with.
Your local supermarket should have bamboo skewers, which might work for support poles.
I would build this out of styrene. I’ve been asked to build a bus station for a friends layout and I’ll be using the plastruct rods, beams and sheets that can be found at most art supply stores.