Since it sounds like the appearance of your stone is important to you one suggestion I have is that you should also consider the hardness of your stone. Diamonds are the hardest (a 10 ), saphires follow next with a 9. Topez are 8. Tourmaline is 7-7.5 (but a diamond is really like 6 times harder than a Topez)
The harder the stone, the less likely it is to get scratched up and dull the stone.
I do not know how the hardness scale works with lab created stones
I did some research on this because my ring is large princess cut Aquamarine (diamond band). I knew it was softer than some of the other gemstones. I know that in a few years there is the possibility that we will have to replace the stone due to wear. I most likely will wear just the band on a daily basis after the wedding to reduce that chance. It is also very high in the setting because it is set "kite" style.
When they first set the stone, the cracked it and are now resetting the new stone.
Our jeweler commented that colored gemstones are great for wedding rings but that you just really need to know all of the pro's / cons that come with them.
My hope is that if we ever need to replace this, I will reset it as a cocktail ring with some other small gemstones and replace it in my wedding set with a blue diamond. A girl has to have some big dreams every now and than