First layout idea...

[GCTTowerA]

I have Linux Ubuntu on my computer and run the atlas software using Wine, which is a Microsoft software compatibility layer. Do they have software like that for the Mac?

Yes, it's called CrossOver. I have used the Atlas software myself and it works okay. Although a native software version would be nice.

Try this software to get your layout planned.

Ah, is there a Mac-based version or equivalent?

What software are you currently using? I know there are some titles like RailModeller.