Hi Sandwoman.
Welcome to The Mattress Underground Forum! 
Thanks for providing your stats and a brief description of your likes and dislikes.
It looks like you’ve been perusing our site enough to arm yourself with some basic information to understand the direction you are “leaning towards” and select durability and quality over the marketing stories consumers are spoon-fed today. The hybrid coil/Talalay is the best choice also for the temperature regulation issues you mentioned. In terms of comfort/support balance, as a combination back/ side sleeper and with being on the light side of a normal BMI … depending on the thickness of the comfort layer(s) above your coil you could do well with either the medium or medium-firm comfort layer. Thicker mattresses can use firmer materials because thickness and softness are very related and work together.
Thickness and softness work together and because thicker layers (or mattresses) can have a greater range of compression and are more “adaptable” … it’s also possible to use firmer top layers in a thicker mattress and still have good pressure relief because of the greater range of compression of the thicker mattress that can create a mattress with a firmer “surface feel” but that still provides good pressure relief and adapts well to the body contours.
It’s hard to say what you’d do well with as only you can feel what you feel on any given mattress and your needs and preferences are unique to you but as you tend to be “more of a side sleeper” you would need a bit more softness however this is compensated the fact that you prefer Talalay latex (which would feel softer for same ILD medium Dunlop) and also dependent of the layer thickness that you select. Also being a low BMI sleeper, you do not need so much comfort thickness. The ticking (the mattress casing), may also affect how the mattress will feel.
Now that you decided on the type of mattress you’d like and the type of materials you prefer, I’d peruse some of our Trusted members to see the latex hybrids they offer and try to narrow in on the mattress thickness, ticking and other personal value equation factors that are important to you.
Let us know of your progress as you move through the selection process
Phoenix