Hi Saz11,
I’m glad the information here was able to help you.
The information you read is is out of date and they are currently using a 1.8 lb polyfoam base layer but either way it certainly wouldn’t have been a weak link in the mattress in your weight range.
While other people’s comments about the knowledge and service of a particular business can certainly be very helpful … I would also be very cautious about about using other people’s experiences or reviews on a mattress (either positive or negative) as a reliable source of information or guidance about how you will feel on the same mattress or how suitable or how durable a mattress may be for you and in many if not most cases they can be more misleading than helpful because any mattress that would be a perfect choice for one person or even a larger group of people may be completely unsuitable for someone else to sleep on (even if they are in a similar weight range) and reviews in general certainly won’t tell you much if anything about the quality, durability, or “value” of a mattress for any particular person (see post #13 here).
When you can’t test a mattress in person and you are uncertain about which mattress or firmness option to choose then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart (which would include Dreamfoam) and who can help “talk you through” the specifics of their mattresses and the properties and “feel” of the materials they are using (fast or slow response, resilience, firmness etc) and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked or other mattresses you are considering that they are familiar with, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs and firmness levels to different body types, sleeping positions, and preferences (or to other mattresses that they are familiar with) than anyone else.
[quote]I plan on getting a sturdy boxy spring like this one here:
I don’t know the distance between the slats in the foundation you linked (it’s not a box spring that has springs) but if they are less than 5" apart then it should be fine (although 4" or less would be better).
Most importantly … congratulations on your new mattress 
You certainly made a great quality/value choice and I’m looking forward to your comments and feedback once you’ve received it and have had the chance to sleep on it for a bit.
Phoenix