Title gives you the general gist of it: my absolutely stunning girlfriend of nearly a decade is on the tall side (a bit over 6') and I would like to give her a good quality pearl necklace for Christmas this year. I was pretty clueless when it comes to pearls, so have spent a week or so obsessively researching here and elsewhere. I've educated myself fairly well on the different categories/types of pearl, terminology, grading scales, relative price ranges etc. and think I am at this point a fairly informed shopper, at least for a 'novice'. I've nailed down mostly what I think I'm looking for (single strand, akoya AAA) which I think should work in my budget (ideally <$1k). However one thing I've had trouble with is figuring out what length to get. Most of the guides out there that cover length pre-suppose a more typical female height of 5'4"-5'6" or so, and I'm not sure how much length it would take to compensate for my gal's additional height so that the pearls would lie appropriately on her neck/shoulders. Also, I'm not sure if the pearl size itself should be "up-sized" as well to look proper? I'll go into some details below regarding her height/build, job, personal style etc. as best I can (I'm a kinda typical guy, and an engineer, so while I try to pay attention to details, 'style' and 'fashion' don't exactly come naturally to me and aren't my strong suit).

Girlfriend is a little over 6' tall. Body type is more Kate Upton than Kate Moss (sexier than either in my opinion). We are both entering middle age (late 30s/early 40s). Longer hair (to middle/lower shoulders) that she wears mostly down. Her profession is interior design, she is currently undergoing licensure and starting her own firm, so needs to present a certain image in the workplace. Also, she comes from a wealthier background, and has great taste, so in general has a discerning eye for quality. Her personal fashion sense favors loose/flowy clothes with a boho touch (though she will show off her curves with some more figure hugging items sometimes). She has lovely shoulders/neck and will often wear somewhat wider/lower necklines (though still modest) or a halter style neck. We live in a pretty warm locale, so not a whole lot of occasion to wear turtlenecks and the like.

Knowing her, I suspect she would not be as enthused about getting freshwater pearls (she likely would see that as the "budget" option), and I can afford to get her nicer things, so I was looking at the Akoya pearls. Based on what I've read, the general style of necklace I have in mind (something like a "princess" or shorter "matinee" length) would end up being in the 20" or so length for a woman of average height. I was also thinking the 7.0-7.5mm size seemed appropriate but am open to advice there if I have missed the boat. As I said previously, my budget is ~$1k (please let me know if I'm wildly off-base there) though I am frugal by nature, so of course lower price is always nice

Sorry for the long post, but I wanted to give any info that might be helpful. And thank you in advance for any help you provide!