Here is my KJ with the newly mounted Surco Safari rack. It is the 45" wide rack. As you can see the rack has cross bars already. I used U-bolts that I plasti-coated black to mount to the stock rails. The rack seems stout with the exception of the interior bottom bars. They are thin aluminum and in between the support rails they tend to flex with a heavy load in the rack. I would say unless you are carrying a heavy very small load (something that will fit in between the support rails) this rack will carry just about anything you want. I plan to have my spare tire up there in the next few weeks.
Franky is in the mail and I have 5 MOABs with MT/Rs mounted in the garage waiting to be installed. I also plan to remove the side steps once the lift and tires are on.

is that the 45 x 60? or the 45 x 50? looks great! im going to be geting that rack within the next week, i like that size that you have