Filling in the Tank gaps

So, I am making a reptile trade and gaining a BP. I have a couple of housing options and wanted to see what you felt was the best. It's a 4' full grown male.Tank: 30 GAL long or 40? I will have a free'd 30 GAL long but could put him in the 40 which currently has a very spoiled Leo :p I also have a 30 or 35 GAL corner tank as an option. That might be a better one becaues I already have a plexiglass top. However it's not long/short like the other two (again.. home to a spoiled Leo, obviously I'd rehome her).Location: For quite he can go in my computer room, I am in there maybe once a day. The only negative for him is that I am sometimes up pretty late on the weekends as a gamer. Otherwise he would be in the livingroom area. If he goes in the corner tank... he'll be in the "living" area.. but in a corner so he might feel more secure. Lighting.. I read the one guide where the person had the ceramic heater (which I understand) and day/night lights. Is there a health benefit for these? If the Ball just gets the usual house day/night is that good enough? I'll buy them if there is a good purpose and it's not just for looks.Thanks!

This is my first Snake and I'm excited! I've been a lizard person for a few years.

Are you set on a tank for the looks? I have found a tub is much better for keeping snakes in the practical sense.

I already own the listed tanks, for now I am happy to use what I already have.

since you already have the tanks then i would use the 40 gallon, i use a 20 long now because my snake is smaller but what i did was i used the black foam board you find at walmart in the school supplies section to cover both sides and 3/4 of the top and bottom of the cage and i use an aquarium background for the back. this helps keep the tempsand humidity where it needs to be. just some suggestions if you have trouble.