My new 40 gallon high, tank.

[Andy Sager]

How many pearl-gourami can I put in a 40 gallon tank? Also do I need the Neons for the middle of my tank? I have fish for the lower of my tank. I notice my Red Eyed Tetras swim in the middle of my tank. I do not want to get too many fish. I do not want to be over crowded again.

You want to either get a pair ( 1male 1 female) or 3 males only. Males can start fighting amongst themselves for the attention of any females in the tank so you eliminate that but not having any in there when there are multiple males.
As for the neons, I believe they will be overpowered by your red eyes so I wouldn't get any. If you were to get more Tetras for the middle, you need to stick with species that will get the same size as the Red eyes. There are species like Lemons, Penguin, Black Neon, Serpae, Black Phantom, Red Phantom and Head and Tail Light Tetras that would fit in your tank. A school of at least 6 -8 of any of these would work.