I mounted mine like this so I have easier access. Plus I didn't want to be looking at something on the wall 3 feet above my head.
I have surround sound speakers that are monoprice and I have no complaints about them
Those 90 degree elbows are so clutch.I buy all mounts, cables, and cable ties from monoprice. If you get the slimline mounts make sure you also order the 90 degree elbows to keep the cable from pushing into the wall. They work really well. I have the elbows on all my hdmi''s and coax.
I'd be surprised if they made their cables in house? Seems like that'd be more expensive.