Q&A: Looking for a Round 1.5 Carat Diamond for $8,500 budget

After studying your site, reading the articles and watching your videos, I feel that I have a much better grasp as to what I’m looking for and also what I can get for my money. I have approximately $8,500 to spend on the diamond even though I would like to try to stay under that number if I could. I will be pairing the diamond with a solitaire setting in white gold and I am looking for a 1.5 carat (or as close as possible), Round cut, J-color or better, and hopefully SI2 or higher that is eye clean with a certificate from GIA or AGN. I’ve been able to narrow down to three choices that I think are the closest match:
https://www.jamesallen.com/loose-diamonds/round-cut/1.54-carat-j-color-si2-clarity-sku-219598?a_aid=dmnd1357
https://www.jamesallen.com/loose-diamonds/round-cut/1.51-carat-j-color-vs1-clarity-good-cut-sku-171451?a_aid=dmnd1357
https://www.jamesallen.com/loose-diamonds/round-cut/1.51-carat-j-color-vs2-clarity-very-good-cut-sku-216170?a_aid=dmnd1357

My girlfriend has been waiting patiently as I have changed careers, went to school and moved around the country, so I want to make sure I get this right, and I would truly appreciate your opinion. Thank you!

Thank you so much for your help. I will certainly recommend you to any of my friends who are soon to be going through the same adventures as I am. I truly appreciate your advice and knew I needed to ask the experts before I went ahead and made any purchase. You and Ira provide an amazing service to us lost wanderers of the jewelry realm. Thank you again!
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I just had one quick follow up question for you. What distinguishes a good cut on a diamond from one that would be questionable? I only ask because there appears to be a slight dark mark in the upper left hand corner of the diamond you sent and I am willing to accept that if it truly is a better quality then a diamond that might be slightly more pricey. Thank you again for your consideration and time.