The 50'' is about ''right'' for the Commander, but I don't see how a 45'' would look all that bad. My rack's 50x60. I couldn't see going to 72'' either, as the price all but doubles for that last measly foot of length..
Here's some photos of my setup. The flat slats make GREAT places to mount lights.
A front shot of my ''version 2'' wind deflector. I lowered the lights. Then, I cut 4'' ABS pipe lengthwise (on a radial arm saw) to make a half-pipe. That was mounted to the front with long 1/4 x 20 bolts to the slats. It got rid of a LOT of the ''Banshee screaming'' past 40 MPH.
The BEST part of all: I have a buddy who works as a welder for a garbage company. It's unreal the stuff he can get for FREE.
The rack floor is surgical grade stainless steel that came from a dam's fish ladder screens. It weighs next to nothing, and makes a great floor. He had large head rivets to install it with. We ruined a couple of tin snips trimming the corners off.
So... what does that shiny stainless mesh do? It blocks about 99% of the sun's heat by acting as a big heat sink. Even in Moab Utah last year in July, we could leave the dogs in the rig with the sun roof open. The ambient temp inside is all but 1 degree higher than outside. It can sit in the summer all day outside of work, and if I forget to leave anything open, there's still NO furnace blast when the door's open.
The SS mesh now lets me throw about anything up there, and the gazillion die cut ''pill capsule'' shapes allow bungee hooks anywhere. It cured my only complaint about Surco racks of which there isn't enough crossbars. The stock rack is only good for putting large items on it. Anything smaller than a Yakima roof pod falls thru. You can buy a crossbar kit to add more, but it's expensive.