The Tempurpedic Cloud is one of the two softest mattresses they make (along with the soft version of the Allura) so if you plan to use one of the Tempurpedics as a reference point I would make sure you clarify which model you tested. The Cloud Luxe is rated as being softer than the Cloud Supreme.
Novosbed and Dreamfoam are both included in the list of the better quality/value online memory foam manufacturers and retailers in post #12 here and both of them (and most of the others as well) will give you good information about more widely available memory foam mattresses that are reasonable approximations for the mattresses they sell that you can use as reference points and will also help you decide which of their mattresses may be the best match for your needs and preferences when you talk with them.