Good move.
Take the old one and bring it to a local rebuilder.
A lot of these newer alternators are easy to replace parts on so could be a DIY as long as the windings aren't broken.
Also my experience with OMIX branded stuff is right about the same as with Crown. Mostly rough, low quality finish and materials made in a far off land by people who don't care about such things.
Be glad you could get it from RA. I wanted to rush order some parts but their catalog struggles with the 4WD drivetrain stuff and it eventually became clear they didn't have the Timken bearing race. Of cours I can't get it locally the way I used to - so a cross country order it is. Hopefully I won't have to drive the Barracuda in the salt and ice - especialy in the city..