Lighting questions

Hi, I am still new to our newest family member Rango. We got him in June with a starter tank and since he has been growing so fast we needed to move him to a bigger tank. We had an old 78 gal fish tank which i am using. My big concern is the lighting. I'm not 100% sure my lighting is accurate. The pet store I just came from told me I needed to change my light bulbs since my tank was bigger.

with the old 20 gallon starter tank I was using a 10.0 UVB 13W ReptiSun light ( ZooMed)
and a blue 60 w daylight bulb which gives of heat and UVA in a Dual Lamp Fixture.

Now with the new tank I was told to use an 13W Reptile UVB 200 light bulb (Exo Terra) along with a 75W Rept Basking spot lamp (zoo Med) in the combo light and in the middle of the tank to use a 75W infrared Basking spot (Exo Terra).

I am not sure where I should place the temperature gage to get a accurate temperature. Should it be by the basking spot?
Also, How many inches should the basking spot be from the actual light?

Sorry so many questions any input would be great.

I would recommend investing in a tube style reptisun 10.0 T5 and having it about 10-12" from the basking spot. The issue with coil style UVB bulbs is that they direct UVB rays into one smaller area which can be harsh on the beardies eyes while he/she basks. You really want a tube style that covers about 3/4ths of the viv. Your basking bulb (UVA) is fine, any regular bulb that produces a white/yellow light to mimic the suns color and produces the correct temps throughout the Viv will work for this.
Is there a reason for the red light?

Thanks so much for your suggestion! The red light was recommend from the owner of the pet store. Every pet store has different opinions so I figured to ask actual owners

Red lights distort their vision. They also do not need a light at night as it disturbs their sleep (make them grumpy, lol)

By the way nice set up, and a very good and healthy looking dragon.