New CVT Source 2013 Subaru Outback

Hello I own a 2013 Subaru Outback 129000 ODO. Unfortunately on my way back from a road trip my transmission went out all of a sudden. The only issue before was a really quiet noise I noticed when I was coasting, but I didn’t think that would cause my whole transmission to shit itself. Other than that it has no other problems. I just got quoted that I should replace the whole transmission for $8400 and I bought the car for $6000, so no way I’m paying that. Anyway I plan on just replacing it myself. I would like to ask for help with it. I’m looking for a remanufactured automatic transmission, or just a cheap low mileage one. As well any additional parts. Overall the process to swap a transmission because I’ve never done it. Luckily a couple of my buddies who are mechanics are going to help me. Most importantly looking to buy a good transmission so any help would be great. I am wondering if the kind people of this community can help me in the process so that I can continue to enjoy my Subaru.