Can't be that hard to make the bits needed if it comes to that.
Someone on here will put pics up if you keep asking, I don't have one sorry
The "bar" to chassis bits are a Box section type unit with a "crumple" section built in, while you would be able to make something like it, building one the will still allow airbags to work (if fitted) would be a bit of a task.
the 07 spain chassis should have two 12mm fine pitch bolts holding the bumper support, they are verticaly stacked and about 130mm apart.
ARB wont sell a mounting kit nor will nissan, how do I know? I went to fit my ARB bar yesterday, cut the bumper, removed the bumper support, mounts did not fit, it is for a 2005-2010 (pre may) spain chassis, mine is a 07/2011, it is different, whole bar is different, so a few frantic phone calls, and "Out of Town" 4WD at wallsend called back to say they had a Deluxe bar to suit in stock, so I spent some coins ans have just finished fitting my new ARB "deluxe" bullbar to my D40.
The ARB commercial bar and mounts I have is now to be sold.
I was planning on putting a 50mm lift under ute this month, but the Bullbar has eaten those funds, so suspension next month, lockers the months after, then I will be due for tyres.
PS, I am happy to post some pics of the mounts if you like, but believe me, it would be a big job to build them, I could have cut and shut my mounts and or chassis, but in the interest of insurance and safety, decided not to.