I think you can hybridize within a variety. I know the different color morphs of the 3-spot gourami (blue, gold, and opaline) will hybridize. You end up with muddy colors if the hybrid is a gold/something cross (I haven't done this but I've come across pics before). Similarly there are different color morphs of dwarf gourami and those should be able to breed together. I don't think you can breed something like a sparkling gourami with a dwarf gourami though.
I have thought about this off and on quite a bit, some day I might do it. The problem is that if they do breed, the young could pass off as one of the adults. You would know that it was a cross, but if you sold it to someone else, that other person might sell it without telling future buyers that it is a hybrid. Everyone knows that blood parrots are hybrid fish, but the danger comes in with less obvious fish, such as rainbow fish, killis, and Endler's.
Plenty of people got burned when greedy breeders would spawn guppies and Endler's together to maximize yields. Customers would buy these fish and keep them in the same tank as pure strain Endler's, and in no time these hybrids would be traded around unbeknown to hobbyists. Same with killis and rainbows. IMHO the issue isn't if you or I are conscientious hobbyists, the issue lies with buyers further down the chain. One bad apple or dishonest person could do a massive amounts of damage to the hobby, and they might even get away with it, long enough at least where the damage done is irreversible. I often wonder why people who don't want hybrids risk the chance by keeping different species in the same aquarium.
If I ever did spawn a hybrid strain, I would not feel comfortable selling the offspring at all. I would have no way of controlling what happens after the fish leave my hands, and I would feel very bad if the worst did happen, because I would be one of the people responsible and to blame. If I ever succeeded and had to many offspring, I would make plant fertilizer out of them or feed them to a predatory fish. Maybe I would trade them to hobbyists who I think are responsible, but I would be responsible if they distributed the hybrids around and the worst happened.
Long speech, I know, but there is a lot to consider if you or I go down this road. I don't think there is anything wrong with hybrids, but all hell can, and has, broken loose when they leave our tanks.
I just want to possess a unique version of gouramis thats all, not planing to distribute any of it to anyone. If someone here has done it, can i get some info on the process? I got 4-5 diff breed of gouramis that all reach 3-4 inches.
Its hard to find any information on hybrids, other than game fish. I think the best luck you will get is by doing what you did, get several species and put them together. Set up a spawning tank and feed lots of live foods. Hopefully you only have one fish per species, but knowing which ones spawn together might be hard if they are kept in a group. Do you have a couple of aquariums to try this out in? Maybe trying 1 male of X species and 1 female of Y species in a tank, and if nothing happens try a different combo. This could take quite a few tanks though, and a lot of time!
I can understand your desire to have something novel but I feel your idea of hybridising species may well leave you disappointed. Hybrids between species are often infertile, or the species may not even produce viable young.
Why not put the time and effort it would take into developing and refining your own strain of 1 species of gourami? The dwarf gourami (Colisa lalia) springs to mind straight away. It is a beautiful fish yet a lot in the stores are washed out, uninspiring examples. There is a range of varities though so you'd have a lot of variation to play with.
By buying a range of varieties from as wide a range of sources as possible (checking that different stores do not simply get their fish all from the same source!) you could outcross and generate some really great fish by line breeding the offspring. With all this effort you may very well also find some novel mutations that will allow you to generate your own new strain too.
It would take a lot of effort and a lot of time and tank space but you could have some amazing results that you would be able to pass onto others as they wouldn't be hybrids but a fantastic strain of one species. Indeed they would probably be in demand bearing in mind the quality of what's out there at the moment!
Unless you have the patience and resources of a professional, inbreeding is the way to go. Start with a pair, lets say a gold and opaline from the 3-spot family. Get them to mate. Match up similars from that spawn. Lets say you find a pair with somewhat longer whiskers (lets just say you do). Mate the pair from the same spawn. And then select for longest whiskers again and keep going.
Beware, inbreeding like this, as in humans, will result in perhaps odd varieties, perhaps sterile fish (problem for continuing your plans), perhaps eggs that don't hatch, perhaps beautiful hardy fish...
To do it right, and get successful varieties, you'll need many many tanks and many many generations (professional). But to just get a funny looking sterile and prone to illness gourami for your show tank, may only take a a couple generations of inbreeding