Don't worry just yet man, mine started doing the exact same thing at around 70k. Two pan drops and filter changes, plus the Transgo shift kit, and it's working almost perfectly at 105k.
My only problem is the car occasionally clunking into first gear, but I'm almost certain it's due to a bad PCS solenoid since it goes away after a restart.. Once I replace that I bet it will be fine.
Get the shift kit and fluid ordered ASAP. Meanwhile no racekar status
I like the napa filter over the filters I've seen from advance. For fluid doesn't really matter as long as it's dexron III or VI. I used Castrols version bought off amazon for like $40 or so shipped with 2 day.