Hi sayedhamdani,
All the better options and possibilities I’m aware of in the Northern VA area (subject to following all the steps and guidelines in the tutorial post) are listed in post #2 here. There isn’t anything new since I’m aware of since the last time I updated the list.
There are no standard firmness ratings between manufacturers so a mattress that is rated as “medium firm” with one manufacturer may be “medium” or “firm” with the next. Firmness is also very subjective so what feels too soft for one person can feel too firm for someone else depending on their body type, sleeping positions, and preferences and sensitivity. The only way to know how firm or soft a mattress feels for you would be based on your own personal testing or sleeping experience regardless of how anyone else may rate it. Only you can feel what you feel on a mattress (see mattress firmness/comfort levels in post #2 here).
I don’t recommend specific types of mattresses or materials because each person has their own preferences and criteria that may be very different from someone else. Your own testing will tell you more about the types of materials or mattresses you tend to prefer than anything or anyone else. What I do suggest though is that no matter which type of mattress or materials you may prefer that it uses good quality and durable materials so that there will be no “weak links” in the mattress (see the guidelines here).
Phoenix