hey guys, i have just got myself a 200L tank and im keen on starting a fresh water tropical setup. (i have had a slightly larger tank in the past which contained 7 goldfish but that didnt really require much of anything to keep it going)
my best mate is helping me as i go along and has gotten me some blocks of peat and a bag of vermiculite for me to be able to turn it into a planted tank.
im keen on a few species of fish and wanted to know if they would be ok together and how many should i have in the tank before it becomes to overcrouded.
i like
black ghost knife fish
neon tetras
bristlenose catfish
not sure what else i can have in there if any extra ?
How're you going to cycle the tank? I know you're not a beginner but you might benefit from reading about cycling on the beginners section.
Try this website as a general idea for stocking - aqadvisor
What sort of approach are you making towards the plants? high tech or low tech? You might want to make a post in the planted tank section on this forum, especially if you're doing a high tech approach with co2 and lots of lighting. I'd also look through the blogs on there to get an idea of what other people are doing if you have the time.
Whatever you're doing, you need to ensure the tank is cycled before you add any fish or you do a fish in cycle with some mature media from your goldfish tank
Hi welcome also Simon seems to have you covered but Im going to disagree with one thing forget about Aqadvisor its quite limited in its functions imo and your going to get better advice on here IMO.
So far as the fish you want to keep, only fish I can see a problem with is the BGK as it gets pretty big and will need a 6 foot tank for life. I would perhaps look at one of the smaller knives like the African Knifefish - there are other smaller growing ones but they are quite rare and could be hard to source but not impossible depends on the resources or shops near you.
The other fish look great to be honest the BN plec is a good choice and a big school of tetras are always good Maybe consider cardinals rather than neons a bit hardier and bigger as well so in a bigger tank you might find them better to look at.
As for other fish some top water fish would be good in there - if your into odd balls maybe a butterfly fish? Or some yellow panchax or if you want some upper water SA cichlids how about some Angels or Festivums? Angels might eat your neons though as neons are their diet in the wild....
Simon seems to have you covered but Im going to disagree with one thing forget about Aqadvisor its quite limited in its functions imo and your going to get better advice on here IMO. 
