When you say Geophagus Surinamensis do you know which species you actually have? Surinamensis are extremely rare in the hobby now and most of them sold are actually Geophagus Altifrons, Geophagus Discrozeter or ocasionally Geophagus Abalios. All of these do get very big 8 - 12 inches depending on species and gender. So I personally think that a 240 would not be big enough for a group of these for life, I also dont think the Barbs you mentioned would be a good match for them as I believe they do better in more neutral to hard water where as the Geos will need softer water to live good long lives and avoid hole in the head issues.
In a bigger tank or with different Geophagus types, instead of the Roseline Sharks, how about something like a school of Hemiodus Gracilis? And instead of the Oddessa Barbs, Bleeding Heart Tetras, Flame Tetras, Bentosi Tetras or Flame-backed Bleeding-Heart Tetras would be good options. It would be a good looking tank as well.
There are a lot of Geo species quite commonly available these days, Pindare and Tapajo Red Heads are 2 of the smallest. Or you could look at some of the relatives like Guianacara, Cupids or Bolivian Rams. There are a lot of other Geo species available in specialist shops now that might be more suitable for this size tank so it would be worth tracking them down if a big tank for your current Surinamensis types is not an option in the future.
Wills
