I much prefer the chromes to the mismatched 'plain' centers you are rolling now.
If those are OEM chrome, and are in good shape, they will look nice. Some parent has a Red NBS on chrome Esky 18s at my son's school everyday, very very nice looking.
If you miss out on them though, consider PC'ing your existing rims and centers a graphite color similar to your GMC badge. I think it would look gorgeous.