Stocking suggestions for 400g tank with rays

[Castermaster]

Evening everyone, our 400g tank is finally in the process of being made, dimensions 9ft x 3ft x 2ft high.
Still trying to get ideas for stocking, read so many contradicting things online.
Having the tank built for a couple of rays, we are thinking 1 leopoldi and 1 black diamond, on top of this we have already just reserved a red tail giant gourami in a local shop.

So the question is what else would you suggest as tank mates, and how many fish, thanks in advance.

 

[FuriousFish]

That's a good-sized tank, Lots of options. It really depends on what you want to keep. An Arowana and a school of tinfoil barbs would fill out the setup pretty nicely IMO.

 

[Castermaster]

Thanks mate, not a huge fan of barbs but its certainly a decent option.