Looking For Interesting Characters

I'm looking ahead thinking of adding new fish to my tank. I'm quite attracted to tiger barbs, I think they are great characters, also have been reading about dwarf cichlids and think they would be a great addition. Perhaps a pair of Kribensis or Cockatoo Dwarfs? Currently I have:

Cherry Barbs (4)
Chain Loaches (4)
Cardinal Tetras (7)
Amano Shrimps (6)

I have 180 l tank, pH8 and hard water. My water company lists hardness as 100 mg/l or 14.01 German deg.

I'm planning to redo my tank in the near future with soil substrate topped with sand and lots of plants, so I won't be adding any new fish until that's ready.

Could I add either Tigers or Cichlids or both?

I've seen the green ones! They are really striking with their red fins and tail and I love the look of them. These are the ones I would get   and 6 is a definitely a minimum.

I like my shrimps and one is fully grown, while the others are in various sizes. I also have a 22l tank, so I guess I could raise them in there and move to the big tank when fully grown.

Five band barbs look similar to tigers but aren't nearly so aggressive. But never having had them I have no idea if they fit your 'interesting character' category.

I have nine five-band barbs and love 'em to bits. They are totally peaceful and hang around together, cruising the bottom of the tank under the crypts looking for bits of food. As for 'interesting charactors'.... there's a bit of half-hearted chasing but that's about it.

The Cherry Barbs are more interesting, and I see you have four. The males go bright cherry red and flare their fins at each other and 'dance' round in little circles, then dash back to 'their' place in the tank... so you would be better off having more of these, at least 3xmales and 3xfemales. Mine even bred in my tank, unbeknown to me. I only discovered it by finding a very small fry living in my filter. I waited until she got big enough and put her in the tank - she's doing really well.