You can cycle a divided tank, no problem. Having a higher bioload will help it cycle faster (if your doing fish in).
You could always DIY a divider. With aquarium silicon it would cost about $8.. with leftovers for other projects.
Personally I dislike the plexiglass. You would need to drill several holes in it to allow for water flow, I'd say 2 holes per square inch. You would also need to make sure the holes are small enough that a fish can't squeeze through or try to. Without having enough holes you won't get the correct amount of water flow and you'll have hot and cold spots along with messing up your cycle.
My other problem with the plexiglass is its clear. This is an either or problem, either the fish will be perfectly fine seeing each other OR they will get extremely stressed out and my tail bite.
I do like the look of plexiglass but I would stick with the mesh.