I have a 65W halogen in a 40 gallon breeder, taller tank than yours, directly over his basking rock and it barely gets to 100.
Right next to the halo I have a Zilla 150W blue daylight bulb, I tried running both to boost the temps.
I tried putting the Zilla 150W incandescent over the rock and it stays at 101.
My electric bill has gone up since I got him just over a month ago, I may buy a 75W halo and try eliminating the incandescent. (I also run heating pads for the roaches, something else I didn't have a month ago)
Another thing to consider, the halo's have different area of coverage, spots, wide angle etc