All of the locomotives the BN painted in the Bicen. scheme are made in HO, providing that you don’t mind the SDP40 being a little dated. Decals are available from Microscale, so it is possible to paint and detail your own.
Athearn Ready-To-Run already did Cotton Belt 9389. I expect next year being the 30th Anniversary of the US Bicentennial there will be more locos out in Red, White & Blue. Specifically the SD45-2s from Genesis in Santa Fe’s Bicentennial Scheme should be out. Stewart has released a U25B in Espee Bicentennial. See Extra 2200 South issues #50-#58 for the potential models. Manufacturers should jump on this for a piece of the Bicentennial pie.
Athearn has done the DTI GP38-2 Bi-centennial unit #1776, and is scheduled to make the GTW 1776 as a GP38-2 in the near future, but the GTW unit was a GP38AC unit so it is another Athearn mistake in matching paint schemes to cars and locomotive that did not exist.