The look of akoyas is different from that of freshwaters. I would recommend looking into the
freshadamas sold by pearlparadise.com; freshwaters don't come any better than that. Freshwaters will also be more durable. If durability is a major factor, you'll be much better off going for freshwater pearls. And freshadamas are probably going to cost less than high-quality akoyas in the same size range. (You can read the thread about my visit to the Pearl Paradise offices to see the freshadamas
here.)
Some members here will tell you not to buy akoyas at all, ever. I say get them if you want them, but know what you're getting.
As you've never bought pearls before, you may want to ask advice from your pearl vendor about the overtone to determine which overtone will actually go best with your wife's skin. Silver overtone will probably give you the whitest color, but it may or may not be the one that will look best
on her.
And whatever you do, don't buy anything from americanpearl.com. Their
misleading information and
unethical business practices render them undeserving of your business.