Hi jrr_brolkien.
Congratulations on your new mattress purchase! 
Thank you for your kind words and appreciation. I am glad that both stores were so helpful and that the new mattress is on its way to you. Not long to wait now!
There is a very wide range of cool gel foams and widely different in their properties and I am sure that City Mattress can easily find the specs of this gel foam for you. Adding gel to a foam would in most cases make it slightly cooler than the base foam it was added to but this would depend on the particular version of gel foam that was used and where it was located. Gel that is added as larger particles that can migrate out of the foam is the least durable version of the gel foams IMO while the gel that is added as part of the foam matrix itself (such as the swirl type of gels) or that use smaller particles that are embedded in the foam struts are more effective and more durable based on all the discussions with “experts” and the feedback I have seen. There is much more about gel materials in post #2 here and the information and posts it links to. You can also read some of the previous discussions about the Royal Jewel series in Post #3 & 4 here.
In terms of foam quality, outside of density (which is the most important aspect of durability) and in your case an inch or so in the quilt would meet with the durability guidelines here . Besides this I would make sure that a foam was CertiPur certified which means that it has a higher chance of being safe. My second quality choice among CertiPur certified foams would be North American manufactured because I know that all of the major North American foam manufacturers are making good quality foams.
I hope this helps you set aside the “regret” and enjoy many good nights of sleep.
I’m looking forward to learning about your new mattress once you’ve had a chance to sleep upon it for a while.
Phoenix