Hi JayD2014,
The most important thing you could do is make sure you have a more detailed conversation with them so you can tell them more about yourself and the mattresses you have tested or have slept well on in the past so they can help “talk you through” your firmness choice.
I would also be aware that you can buy the Ultimate Dreams latex either fulfilled by Dreamfoam or fulfilled by Amazon.
If you choose Dreamfoam fulfillment then you would receive the pillow bonus that they offer the members here but there would be no return (or if you did then return shipping would be costly).
If you choose Amazon fulfillment then you would qualify for the Amazon large items return policy so you could return the mattress for a reasonable cost (see here) if your firmness choice didn’t work out as well as you hoped but the cost is a little higher and there is no pillow bonus.
Phoenix