Hi Falcon,
Firstly, i will come back to you about the exact measurements of the corner top sidepanel / marquee area.
And about a fluorescent light, you can just but one from Gamma or Praxis that fits in.
I won't buy a led or anything, but a real tube that works on 220 volts.
You will probably need a (stekkerverdeeldoos? / outlet divider?) anyway, since you need 220 for the TV, for the PC, maybe a speakerset.
So you can plug it right it.
The tube i bought (50/55 cm in width i guess and priced at about 17 euro's) works perfectly. Light is really bright but not to bright, and evenly emited.