Your tank looks very well!
In My Opinion your tank looks quite bare. I really love the look of moderately-heavily planted tanks and drool over almost every one I see. I would recommend a bit more plants. You cold easily start out with a clump of hornwort, or java moss. And they will spread quickly
As for backrounds I would recommend either a natural rock backround as these are very attractive and look stunning. But 3-D backrounds also minimize the swimming space which lowers the stocking potential. Or maybe a black backround to contrast the bright colored fish and plants.
As for stocking. You stocking has virtually no flaws. The only recommendation that I have is to purchase about 3 more spotted cories so they feel more secure. And will be much more interesting to watch.