Hey,
Good on you for making something special. It looks great so far. I'm not sure how large your scubbie is going to get but I know they are very arboreal.
Don't be too concerned about the separator in the AP cage should you decide to go larger. I have a custom built Pro-Line cage that is 6' wide x 30" deep and 2 feet tall for my reticulated python. It is a double cage and there is a separator between the doors. My guy is SD and dwarf with just a little mainland in him. These guys are very arboreal as well.
I think scrubs and retics have similar habits. Scrubs are probably even more arboreal.
Arboreal options make for great display opportunities.
AP makes a great cage. Now that Pro-Line is finished with the cage bizz, I'd go AP without question.
Congrats on the scrub python. El Ziggy is a good source of info if you have scrub questions.