Most people here do the dual element mod.
I did the 900 watt, and have done 2 smokes with it.
If I had to do it again, I'd have done the dual element mod. I decided on the 900 watt because I figured the fins would transfer heat into the air better than the regular elements.
I even talked to Tempco, who makes the 900 watt element we use (and they make elements similar to the regular Bradley elements). He said finned elements transfer heat into air better than infrared tubes (which heat objects better).
All of that said, the finned element only heats on about 9" of the element, whereas the Bradley element is longer.
So I'd say its a tossup. Pic the one you feel will be the easiest to mount based on your skills and tools. I drilled 1/4" holes thru the back, used 3/4" long steel bushings to hold the element away from the back wall, with fender washers on inside and outside to spread the bearing surface over a bigger area.
A fan would be a great idea. Some don't. But you're adding a lot more heat to the bottom, so your top to bottom temp spreads will be wider.