Custom terrarium lighting!

Hello! I have been reading this forum for quite some time, it has been a great resource of information for my bearded dragons. This is my first post , I have a couple of questions about UV lighting for a custom terrarium we're about to built, thought that a pro might be able to help.
So, size will be 120x45x35cm (LWH, around 47x18x14 inches), two floors, back and one side will be wood, front and other side glass.
We will be using the Exo-Terra Light Cycle unit as a ballast, timer and controller. This is good for two T8 or T10 tubes. Thinking of ZooMed T8 ReptiSun 10.0 UVB.
So, here's the questions:
1) Will one 91cm/36inch tube per housing suffice, or will we need to install both on one floor and get another Light Cycle unit and a couple of tubes for the second?
2) Will installing the tubes on the ceiling on brackets be ok, or will we need to wire the Light Cycle unit to a reflector (for example T8 ReptiSun Terrarium Hood), install the tubes there and mount the hood on the ceiling? I mean, will the 91cm tube without a reflector do the job, or do I need something more?
I absolutely love my beardies and want the best for them, waiting a bit to get one more set (IF needed) of controller/tubes/hood is not a problem, but I also don't want to overdo it, since I don't know how much light these tubes produce, how much UVB, how much the beardie needs and how much is good for this terrarium size.
Thank you a lot for any help!

I would consider building it with more than 35cm of height to allow for climbing spaces to be installed. I would also consider using a T5 controller and UVB lighting but if you stay with the lower space a T8 may be OK with a reflector fitted to it. With a reflector they have an OK output between about 15-20cm. They decay more quickly though so the bulbs will need to be replaced every 6 months or so. I suggest reviewing the guide Taterbug put together which shows estimated outputs of different lighting combinations. It may help you find the right fit for your setup https://sites.google.com/site/thelizardmadness/lighting-guides

Thank you so much for your reply!
I'm going to read the guide right now and review my options!
Thanks!

Thanks again for the info, much appreciated, I end up ordering a T5 with a quality reflector, saw that the output is much better this way, thank you!

That's great to hear. I think a T5 will serve you well.