I like the round tube stuff as shown in the pic, not hard to fabricate at all.
Agreed , lots of bracing and tieing into the roll cage is good.
A lot of guys with street type cars seem to prefer the rectangular tubing rails for some reason.
The mandral bent rec tubing is easier for the manufactures to put out, and sell to guys that want to do the job themselves.
It is not difficult to make up a sectioned frame rail and weld together.
The trouble with these kits and frame rails as supplied is they are all a universal fit, which means, it fits everything, but fits nothing well....