Hi diddeetip and welcome to the Mattress Underground 
As you may have already read, any mattress you choose will be unique to you, based on your Stats (height, BMI, sleeping positiobn(s) and any underlying health conditions) - thanks for providing those! - and your PPP (Posture and alignment, Pressure relief and Personal preferences).
The latex for less medium king is a flippable latex mattress with an organic wool and cotton cover, with a medium and firm side. An all latex mattress has a different feel from a hybrid coil and latex mattress; one benefit of a DIY project is the amount of ‘fine tuning’ you can do, with a little patience, to customize your mattress to fit you and your husband.
With your husbands slightly higher BMI, you want to ensure proper support as well as comfort. Memory foam does tend to sleep hot; as you can see comparing the Mattress Specifications You Need to Know to the Mattress Durability Guidelines, latex is one of the most durable materials you can have, and it’s also very breathable.
Any HD foam can be used as a base, depending on your frame or bed platform you can even have the coil layer without a base. For higher BMIs, a lower gauge coil is recommended, but it’s a matter of how it feels to the sleepers as well as support. Either the 2" or 3" medium latex could work for you…keep in mind Talalay has a very different ‘feel’ than Dunlop; it’s considered ‘bouncier’ (think of the difference between angel food cake and pound cake). A DIY project can demand a bit of patience as you may need to rearrange layers to suit your comfort needs to ‘zero in’ on the right build.
As far as hotel mattresses - it is almost impossible to recreate the feel of any given hotel mattress…not only are they built exclusively for that hotel, and do not disclose many, if any, details on their construction, but even if you found a close match, one single added or moved component can give it a completely different feel. Better to dial in to what you and your husband find supportive and comfortable. Make sure to choose a manufacturer with good exchange and return policies in case you need to take advantage of them.
Several of the Trusted Members of the site have great DIY resources like DIY Mattress, DIY Natural Bedding and Latex Mattress Factory among others, can help guide you in choosing layers for your specific body profile, so that your build will provide comfortable and supported sleep for many years.
~ Basilio