That should be no problem, any AG wheel supplier in your area can make the rim for you.
They will need your Old rim and disc in order to properly locate & weld up the 6 mounting loops inside the rim... they will even paint it up for you.
Someone has used calcium in those wheels in the past. If you are going to load the tires, use Rim Guard (Beet Juice). Never rusts, won't freeze and it's heavier than calcium. KennyV