Those springs would be excellent for this type of application, and I especially like the soft-close aspect. However, the issues I have with those spring hinges are:



The top on my box has sides. Small, but sides nonetheless. This would require building out an extension (anchor block) on the top to attach these.

With no weight rating I'd have to build then try. Not a good option. I'm also really doubtful they'd be able to handle the weight of my ottoman top unfortunately.

I believe the foam and upholstery may add up to another 24lbs to the weight of the top. I just weighted one of the leather covered pillows for my sectional and it's 12.2lbs, so I'm doubling it to be conservative.

I'm still working on the illustration to show the top open and will put together some samples of positions for the gas springs. I'm totally open as to how they'll be mounted at this point. I'll also post up a photo I took of a commercial product.