Perhaps you could use one of my planes that I created for my cosmology.
Andara: Plane of the chosen people
In the second age the gods could walk on earth. The demons lost the first battle for the rulership of the universe and the gods created the world. The world was in bliss and the first ones were blessed by the gods with their gifts, different gifts for the different followers.
But some gods conspired with the demons and destroyed the crystal mountain top of Kai Khara, the seal to prevent the entry of the demons and the conduit of power for the gods to the mortal reams
After the war against the dark gods, the gods had to leave the mortal realms, because they were so weak on earth, other gods could overcome their realm in the heavens and take their place. They had to leave. But the first ones were in peril , too. Their gifts from the gods now were a curse, because without the conduit of the crystal mountain and the departure of the gods, they would lose their powers and would die, their body was too hallowed to survive without the divine spark. They had to go too but could not enter heaven permanently.
So the gods created Andara, the blessed realm. It was near the heavens but still a separate realm, so they could still be called to earth when there is need.
The plane of Andara is filled with joy and light. The chosen of the god of the sun, the Solandril, reside in cities all over the plane built of beautiful marble and gems, filled with light, but their capitol is the Shining Citadel, the Sun of Andara which is slowly floating thru the plane. The stars of Andara are cities,too. These are cities filled with the flickering light of the moon goddess, greatest among them is Sharalan, where a sacred artifact is kept, a shard filled with the power of lost Kai Khara. The followers of the goddess are a solemn lot, seldom coming down from high Andara to share time with their brothers.
The other chosen of the gods reside primarily on the soil of Andara. There are the followers of the god of nature who keep to the wilds and merge with the plants and the followers of the god of animals in constant animal shape. The Alaar, chosen of the goddess of love and joy are all over the plane, celebrating and inviting mortals to join in (happened to my party, they don´t know much about their first planeshift).
Surrounding Andara is the shimmering sea and the lightless sea, so called because the shining citadel never goes there.
Perhaps you could use Andara in some way. Erecting beautiful cities in the landscape filled with lantern archons, celestials guarding the shining citadel and wild but benevolent good creatures out in the wild. The lightless sea could be a border to the plane of shadow, something like the deep ethereal.