Tested VONO SpinePro 800 ok not bad, price also can nego down a bit.
Then tested SpinePro 1200, checked the specs with 800, some difference indeed and felt better on 1200.

At first tested VONO Luna - not bad quite comfortable but the 11" thickness meant needed to change all bed sheets

In the end went for Back Relax 2 instead. Haggle for discount and got free pillows thrown in.

Side sleeper - better test out the firmness of the bed see whether ok or not. Otherwise you'll end up sore back, neck and shoulders.

Mattress is too firm, can add latex on top to solve the problem, but mattress itself sink and lose support no chance gotta change already.

Anyway, mattress use 10 years good enough already lor.

Good luck hunting!