Advice Needed for a Temporary Lighting Situation

Good evening all. I have a 20L tank from Petco. I need some advice on which of the lights I own should be used. I have a 30" aquarium hood with a 24" Reptisun 10.0 T8, and then a 24" Reptisun ballast with two different bulbs, Reptisun T5 in both 10.0 and 5.0. I have ordered a custom 4'x2'x2' enclosure, so I am wondering which of those 3 lights I should use in the couple weeks I am having to use the 20L while I wait for Sir Henry's new home. I think, considering the tank is 12" tall total, that the T5 10.0 is too strong. The aquarium hood is too big to actually fit inside the tank. Right now I have the T5 5.0 on top of a metal, large screen cover from ZooMed. Am I incorrect in thinking the T5 10.0 is too strong? Should I stick with the T5 5.0 or go back to the aquarium hood?

Stats:
Daytime temps
75-80 cool side
88-91 hot side
103-110 basking spot

Nighttime temp drops to about 70, and the house thermostat is set to not allow temps below 66.

Temps are taken with an IR temp gun. I also have a digital thermometer/hygrometer with an in-tank probe.

The humidity varies from about 43 first thing in the morning when the lights have been off all night, to 27 or so during the day.

Thanks for any help you can give.

Sorry, forgot to attach the picture of my current set up. I can't wait to get Sir Henry out of this tiny thing!

I would use the 5.0 bulb on the 20 gallon but it should be unobstructed- decor piece should be 6-8 inches directly underneath it -- when I had my 20 gallon set up I took the screen off set the UVB width wise on one end by the basking light so he was under both -- I used a 75 watt bulb clamped to the end of the tank --- or you can take and set the basking area up towards the middle of the tank w/ screen on it half way so the basking light can sit on the screen w/ the UVB going width wise w/ the screen off on the UVB side -- it is up to you -- W / the T 5 sitting on top of the screen now 30% is being blocked by the screen - usually they can sit on top of the screen as long as the holes on the screen are a wide hole type -- and then the basking decor piece needs to be 8-10 inches under it --

Thank you so much! Your help is very much appreciated. That was the light I was leaning toward using. I have things switched around now to get the cover out of the way, and anxiously await the new enclosure.

Part of my trouble deciding was not knowing if that cover was considered a large or small screen. To me, when I think small, I think of something like a window screen, and it was definitely bigger than that. Out of curiosity, what would be considered a large screen? Something like chicken wire?

Yes chicken wire would be considered large screen -- you dont want fine mesh like a screen door