If CX was to offer permanent residency ("green card") to SO's who'd be based in the States, CX would have to 1) prove to the Dept.of Labor there are no suitable and willing candidates found among locals, 2) pay prevailing wage.
You can try to accomplish No.1 by openly advertising the position(s) and turning down all applications from locals using criteria locals can't meet; to accomplish No.2 you probably will have to do a survey of local "equivalent' airlines and their wage structure to come up with a prevailing wage for the SO position.
Not to say CX doesn't have experience in immigration issues, but I'd guess the U.S. DOL and INS are quite a different animal compared to what CX deals on a daily basis.