Join Date: Oct 2010
Location: Victoria, Australia
Going by the tank specifications the OP has provided, soft acidic water, lots of cover and suitable tankmates, there is no reason not for them to choose a wild betta species.
I have had hands-on experience with at least 15 different wild species and have successfully bred at least 7 of these, so yes I do know what I am talking about. It is one thing to read up on websites and in books about a subject, and it is another to have actual personal experience to go by.
If you have the environment right, wild bettas are a heck of a lot easier to care for then splendens. My wilds rarely have issues with health and the only reason I lose them is through their darn suicidal jumping.
I have four wild betta males living together in a 10 gallon tank. They have spats every now and then and someone will come out with torn fins, but they don't actively hunt down and kill each other. I have had only one species of wild betta try and kill each other, and that was ideii. They are known however, to be very aggressive towards conspecifics even to the point of the female killing the male or vice versa. But even they after a period of time within eye-sight of each other could be safely housed together without harm.
OP if you can get your hands on imbellis I would definitely recommend you give them a shot. Wild bettas are truly beautiful in a different sense to the gaudy splendens and when in full colour and on display it will make you wonder why you even bothered with the splendens in the first place!