Yeah we can see the picture, it's at the top above the text.
How much flow are we talking? It doesn't really look like a strong current in the pic. Keep in mind, the fish typically in strong current water in nature have their water highly oxygenated where as from your pic, the water surface is rather still and I assume your water might be more on the warm side.
By the way minnows like cooler water and that German Ram in your tank likes warmer water, but hey I keep some fish out of their preferred temp range as well (hillstreams and rams) and mine are in great health. But the dissolve oxygen causes some concern if fast current fish will do so well in that tank.
From the pic I wouldn't really consider it high flow like a river tank. I think you could better air/position the powerhead to better circulate the water through the entire tank like others have done and it wouldn't be considered so high flow and common fish would be fine in there.
Fish that are normally in gentle current waters actually like to play in high current waters often as a form of fun/entertainment/exercise, but they should have calmer water areas to rest in and not constantly be fighting against the current just to stay in place.
But if you do insist on high current species, do some research on fish from naturally fast flowing rivers, etc. (again keep in mind, fast current waters are usually cooler and highly oxygenated), but as you mentioned, minnows and hillstream loaches (a very large variety might I add) come to mind. I am not all too sure of higher water column fish though, maybe some hyperactive danios? (zebra danios). I can imagine the dwarf neon rainbows (Melanotaenia Praecox) doing well in there.
Torpedo shaped bodies doesn't necessarily mean they tolerate high currents a lot, it's just they are more streamlined/hydrodynamic to swim faster in water, though they could probably handle it for a while, I don't think they would do so well after they tire out from constantly fighting against the current. As for vertically flattened fish, doesn't necessarily mean they can't handle current as well, now angels and discus, yeah they aren't the most efficient swimmers (although I have seen some swim surprisingly fast), but fish like hatchetfish, coin/disc shapped tetras and sort of tall and "flatish" rainbowfish can swim fast. Horizontally flat/compressed fish like species of hillstream loaches can handle fast currents.