Illipe butter, what its known as in most of the rest of the world, is a completely different tree, Shorea stenoptera, and is mostly native to Indonesia and a few other places.
Mahua, or mowrah, is from both Madhuca trees, very common in most parts of India and less anywhere else.
SAP values will vary, depending on where the tree is, when stuff is harvested, etc. I'm going through the same research difficulty with a local oil as well. You will need to do a lot of small batch testing once you get a supplier of a consistent product, otherwise you might need to test every single time (usually the problem with unrefined oils direct from source but I love using those lol).
Haven't tried either but I did lots of research because I wanted to try them, and because I'm trying to import the Indian butters and oils coz they're very hard to find where I am now.
Not sure price wise if it's feasible for you guys, but Veda Oils in Delhi has competitive pricing and they sell bulk, and they have a lot of info on their products, plus free shipping anywhere in India if you reach 999 INR. They have butters, carrier and essential oils, etc.
There's also Lime Art in Coimbatore, smaller company so somewhat pricier but they also have relatively good pricing (compared to here, even if I include shipping costs). My SO has been there to check out stuff for me, and they're very informative as well, and have stuff that maybe hard to find elsewhere too.
If you're buying in Bulk there's also Aarnav Global in UP, but they're an exporter so might not have in small quantities but you can check. They quoted for me mango butter as low as 7kgs so maybe they can cater. They have a lot of products, including essential oils, carrier oils, butters, etc.
If you're looking to sell your soap, by all means to help out the small time suppliers by buying straight from them, but make sure you've done your thorough testing....