Uranus and Neptune

A little hard to follow your plan at first, but in the end a ring world type structure? The gravity should be very reasonable, Uranus is 0.9 G and Neptune is 1.2 G at the 'surface'. Interesting, one issue is you'd always have a 'managed' habitat and if something goes wrong it can go very wrong. Not that that can't be overcome, but the less 'management' that's needed the better. Technically if you super Earth water world Uranus or Neptune, it will remain warm for a very very long time. Sunlight via mirrors, or preferably fusion at these distances from the sun, would need to be managed but that's the case for both. Plus the ring needs manufacturing for all of the real estate, whereas once you get the atmosphere removed and an Earth friendly one in place most of the planet is available at once. So the question may be removing the atmosphere vs. manufacturing a buckyball ring? Someone would actually have to calculate the costs and benefits of each, not me! :)
Brooks