Well then if the top is glass thats gonna be hard. Your better off finding a new tank honestly unless you can drill holes into it and mount a 46" uvb reptisun t5 HO 10.0 tube light inside without shattering it. Though you could make a top for it by yourself without risking the glass shattering by removing the glass top (assuming you can) and either trying to find a 55 gallon regular top or getting wood and mesh and making your own top by drilling the mesh to the wood. I'd personally use a more open mesh rather than one with lots of tiny holes, its a bit hard to explain but it'll let more uvb through if you do and then ussing mesh with tiny holes on the sides where the wood is so it may stay together better.
Only thing you could place on top of the glass would probably be the 150 watt or so heat source, guessing 150 watt since usually in a 55 gallon tank the height is 20 or so inches and with that bulb it the bottom of the warm side to around 88-90. However im not sure how much glass can handle when it comes to heat.
Also by uvb lighting vs basking light i suppose you mean which do you need or something, you need both, usually a reptisun t5 HO 10.0 tube light (around 46" bulb and fixture with a reflector for a 48"l tank) and then either a MVB (produces uvb and heat) or a regular bright basking light (just produces heat a bit more compared to a MVB that ive noticed). With a mvb you'll still need a uvb tube light.
As for heating your enclosure at night you dont need to as long as it doesnt get below 65f. And if it you should a CHE (heat emitter, produces no light) the reason i say a che and not a "infrared" night time bulb or those blue, or black night time bulbs is because beardies can see those completely fine just like we can so it disturbs their sleep.
