Will the high output and the 150w basking combined be too much? Also I was going to put the UVB fixture just on top of the screen lid for now would that be ok?
And for that fixture you linked is it the mind that clamps on to the enclosure (in other words I wouldn't be able to rest it on top? It would work for the reptisun HO right?
I use a T5 UVB bulb and a 150w basking bulb and they work well together. The trick with the basking bulb is to get it to the proper wattage and height to provide proper basking spot temperatures. The UVB just combines with the white basking light to provide levels closer to natural sunlight. The T5 bulb is effective at 12'' above the basking spot even through a screen top. The fixtures I posted can be left to sit right on top of the screen or they can be suspended above the screen using a grow light stand (this can be home made out of PVC if you wish). The T5 ReptiSun 10.0 will fit into the Sunblaster as long as they are both the same length. Here is a photo of how I have mine set up for reference. The basking light is on a lamp stand to the left. UVB is across the front (if I had it to do again I'd get one that only runs half the length) and seasonal nighttime CHE is on the stand to the right.
The photo of the sun blaster fixture on Amazon is accurate, it will not sit on or clamp to the screen/tank edge. The ends are rounded and the reflector does not wrap entirely around the bulb. I have two of them, they are great fixtures but you'll need a stand for it.