2007 Hyundai Tiburon GS Transmission Issues/Transmission Swap Specifications?

[clueless2112]

I bought a 2007 Hyundai Tiburon GS recently for cheap. I think it may need a new transmission. I am getting it diagnosed (and only diagnosed) later today at the dealership, but I am wondering if there is specific knowledge a mechanic needs for this car's transmission swap. It is an automatic, 4 cylinder, 2.0L transmission. I want to say I read somewhere (can't find it now) that it needs a specific fluid (maybe the transmission fluid?) That was actually some type of Mitsubishi fluid or something? I also thought I had read somewhere that it has something special about a shift-something? I don't remember what it said, and I can't find the info now. Does anyone know anything about these cars? I want to make sure whoever I send it to knows what they are doing with my car. Also, if anyone has an opinion on what could be wrong, it would be greatly appreciated.

Here's what it is doing:
-The car can be driven around for about 15 minutes or so with no problems, then all of a sudden, it will start jerking when shifting into 2nd gear it seems.
-The jerking was very hard (the hardest I've ever felt in a car with transmission issues) and it almost seemed to downshift (I don't know about the rpms and what-not, I'm a girl, cut me some slack)
-I brought her in to the mechanic and they fixed an O2 censor, I believe (my boyfriend handled it as I am completely inept about cars :/) which they said could be the cause of the issue?
-After I got her back, the car, yet again, showed no signs of it until I drove it for a while (temperature related?), And then it started jerking at 2nd gear again, ONLY, not even close to as hard as it was before, but it is happening more frequently now? (Something to do with the O2 censor work?)
-The car was originally throwing up vacuum leak codes (but they fixed the O2 censor?)
-The mechanic said the oil and the transmission fluid looks fine, and that actually the transmission fluid looks so good that they think it has been flushed or drained and filled recently

I know this may not be much info to go off of, but does anyone have an opinion on the matter? I would greatly appreciate any advice.

Other weird things the car is doing, but not sure if it is related or not:
-When I get the car up to 50mph or more, outside air seems to blow through my vents into the cabin of the car. The car defaults to the outside air circulation button. This also creates air rushing noise (quite annoying)
-Side mirrors aren't working
-OEM stereo/faceplate is still in the car and is either not hooked up properly or there is another underlying issue as it acts like there is a short in it and I cannot get it to work to test my speakers

If I think of anything else I will update. I have not been able to really drive this car yet, so I don't have much to go off of. Thanks!