I haven't kept them, but they are part of the unimaculata complex and I have kept ideii and unimaculata who are very similar. I don't know the answers to some questions as I have never owned them, but I have linked to sites that may help you further.
Breeding antuta in captivity is completely possible. Being wild bettas you can generally keep a male/female pair in a tank together and they will spawn whenever they are ready. The difficulty with large mouthbrooders is getting them to hold to term. Most tend to swallow their first few batches of eggs, which can be frustrating for you!
Your male needs to be kept on a nutritious, high-protein diet as he won't eat while he is holding (think the holding period is around 14 or so days) and you need to give him a rest in between spawns as he can suffer if he is not allowed to regain condition.
You can have them in a tank with no filter, but I found my larger mouthbrooders actually seemed to prefer some current in their tanks.
Males will grow larger, generally have a bigger mouth and show more iridescent scaling around their head.
I keep my wild betta tanks in the mid seventies. Wilds seem to prefer it slightly cooler than splendens.
Most important thing is that your tank is completely covered. The larger mouthbrooders can easily jump out of quite small gaps and I have lost several unimaculata because of this. I cling wrap the tops of all my wild betta tanks and then put a glass lid down over the top.
Here is a site with some more info