First of all about the neon thing - just like with angels, if you raise them together they may not get eaten BUT - discus require a high temperature to remain healthy. Neons, on the other hand, cannot take these high temps. As such, neons and discus are simply not compatible. Cardinals are the most common candidate for discus tankmates because they are both large enough to not get eaten and can take the temps.
As for keeping them in groups - wild discus are normaly found in large schools. Juvenile fish, when kept alone, become very skittish, shy and, as a result, stressed. If kept in too small a group, they fight to establish the pecking order and all the pressure ends up being placed on a single fish - which usualy results in the death of that fish and, subsequently, a smaller group. Then the same happens to the fish in that smaller group and so on until you only have one left and you're back at square one. When you have a group of at least 6, this aggression is devided between all the individuals so that no single fish gets bullied. Besides this, you can't sex young discus visualy so getting a group means your chances of getting a compatible pair are higher. Adult discus, once they pair up and start breeding, will behave like most any other cichlid and become territorial towards their tankmates - including other discus. They also form an attachment with their mate so that the pair kept alone does absolutely fine. However, I wouldn't keep an adult completely alone even though their need for the security a large group provides is less. Occasionaly you'll come across an individual that simply happens to be 'anti-social' but this is rare and shouldn't be encouraged. You also can't tell that this is their character until you've actualy kept them as a group for a while so this is no excuse for buying a single fish!
I also want to point out that the word 'barb' describes a huge group of fish. Not all barbs are nippy. Tiger barbs specificaly, however, are notrious fin nippers and not good tankmates for any slow-moving or long-finned fish and deffinately not for discus which realy do need to be with peaceful, non-boisterous tankmates.
You obviously did not research discus prior to this post in much detail. If you are seriously considering them now, I suggest you do. Do a google search, ask more questions and maybe get a few good books as well. These are a fish that you can't afford to rush into (though they are slowly getting hardier - and cheaper) and you'll find a lot of people who keep them have very different views on them and on what the right way of doing things is as well. I would strongly urge you to take your time exploring all their views before getting any of these fish.
As for keeping them in groups - wild discus are normaly found in large schools. Juvenile fish, when kept alone, become very skittish, shy and, as a result, stressed. If kept in too small a group, they fight to establish the pecking order and all the pressure ends up being placed on a single fish - which usualy results in the death of that fish and, subsequently, a smaller group. Then the same happens to the fish in that smaller group and so on until you only have one left and you're back at square one. When you have a group of at least 6, this aggression is devided between all the individuals so that no single fish gets bullied. Besides this, you can't sex young discus visualy so getting a group means your chances of getting a compatible pair are higher. Adult discus, once they pair up and start breeding, will behave like most any other cichlid and become territorial towards their tankmates - including other discus. They also form an attachment with their mate so that the pair kept alone does absolutely fine. However, I wouldn't keep an adult completely alone even though their need for the security a large group provides is less. Occasionaly you'll come across an individual that simply happens to be 'anti-social' but this is rare and shouldn't be encouraged. You also can't tell that this is their character until you've actualy kept them as a group for a while so this is no excuse for buying a single fish!
I also want to point out that the word 'barb' describes a huge group of fish. Not all barbs are nippy. Tiger barbs specificaly, however, are notrious fin nippers and not good tankmates for any slow-moving or long-finned fish and deffinately not for discus which realy do need to be with peaceful, non-boisterous tankmates.
You obviously did not research discus prior to this post in much detail. If you are seriously considering them now, I suggest you do. Do a google search, ask more questions and maybe get a few good books as well. These are a fish that you can't afford to rush into (though they are slowly getting hardier - and cheaper) and you'll find a lot of people who keep them have very different views on them and on what the right way of doing things is as well. I would strongly urge you to take your time exploring all their views before getting any of these fish.
and always try to do reserch(although in the case of my tiger barbs they were rescued so i didnt really have the time 
) )i am concidering discus but i need to do alot more reserch first!
