I'd prefer the nicer setting, but that's part of why I went with a sim
The Amora OECs are gorgeous and very diamond-like, and a killer setting is more important to me than a valuable diamond.
Just a word on resale value, though, you will probably lose money on either one. A member here recently bought a graduated frenchie setting for about half what it cost to make, but I have a suspicion that the seller could have gotten a bit more since it sold so quickly. You'll definitely take a hit, though, as people won't want to buy a setting made for someone else's stone and worn by someone else unless they're saving a significant amount of money.
You might think a diamond will hold its value, but you'll never be able to resell a diamond for what you paid for it. The only way you might come out somewhat even is if you bought a diamond secondhand directly from its current owner and then resold it yourself later. Any sort of retailer or dealer will be selling at a premium and will only buyback at below wholesale price.
I'd go with what you love, not with what you think might have better resell value. Jewelry makes for rather poor investment pieces, I'm afraid, so just get what you like and enjoy it!
Edit: Just saw the part about the upgrade policy. That does change the game some. Do you anticipate wanting to upgrade in the near future? If so, you might consider getting the diamond. You can still get a very nice setting for 2k, though! No french cuts, but a beautiful halo is certainly an option. It won't be Leon Mege or Victor Canera, but DBL, Schubach, Wink, or David Klass might fit the bill!