Hi Lquijano,
Welcome to the Mattress Forum! 
(I deleted your other post in the other Arctic Dreams thread, as it was a repost of this one.)
I’m sorry to hear about your health issues, but I’m hoping that you’re feeling better. It’s understandable to want the best mattress on a tight budget, and the Arctic Dreams does represent one of the best values in the lower budget ranges. The Arctic Dreams comes in an 8", 10" or 12" versions, described by Dreamfoam as Medium-Firm, Medium, and Medium-Soft, respectively.
Dreamfoam is a member here, which means that I think highly of them and their knowledge and products, so my best advice to you would be a detailed phone conversation with Dreamfoam and describe to them your sleeping posture and any particular needs you expect to get out of a mattress, and they will use their experience based up the thousands of people in similar situations they’ve previously helped and will try to best match the appropriate Arctic Dreams that they think will give you the best chance at success. You didn’t provide me too much information on your sleeping style, preferences or needs, so I would defer to the judgement of Dreamfoam.
Regarding total height, the 10" has 9" of main foam pieces, and the 8" has 7" of main foam pieces. It is true that there can be slight variations (+/- 1") in product, but what you may have read was a description some time ago where there was a very short run of mattresses where the glue between the layers wasn’t fully cured before the item was compressed for shipping, and that issue was quickly resolved. Of course, if you did receive an item that didn’t in-compress correctly, it would be replaced under your warranty immediately.
You are correct that the Energex polyfoam is a good quality polyfoam that does allow for better repositioning than memory foam, and it is more breathable.
Post #4 here and the posts it links to also includes many of the other better lower budget online options I’m aware of as well.
I hope that information is helpful to you. Please let us know what you end up deciding to do.
Phoenix