You could sell it after a while like ur devil. Have a combo of dats and bass with flag tails. That will make it look active and colourful. Before that I honestly feel the lights and background should be your top priority.
well first of all, your tank stock looks good as it is, but if you want to add something that will pop, i would change the background and get some nice vieja's maybe a nice male synspilum, or argentea
Your tank is looking more like that of justarn's previous tank if you add a giant gourami. The wow factor would be if it's a red tail giant gourami. However, be careful with getting a GG. Some cannot work with a community. So it will be an expensive experiment that you need to try. If it works, then it will look wonderful. Just be wary that giant gouramis are treacherous bastards. They do not flip out immediately. It may take months before you come home to skinned and de-scaled cichlids. A flagtail is also a good addition. They only work in solos or groups of six or more. Flagtails kill each other in pairs or trios. They grow large too at 16" so a group is definitely a large bio addition. Well, as an alternative you can get the tinfoil barbs. They are very good dithers and most importantly, cleaners of excess food. I do not recommend them much, though, given your current stock.