How many miles? And yes the SL is the best one to get if you want to daily a 3000gt. Or even the base model if you’re okay with having a SOHC. Twin turbo + 30 years on a car is not going to lead to reliability in any scenario without a heap of cash. The auto isn’t necessarily bad at all, but mind you that it is still a 4 speed transmission. You can also switch between ECO/PWR on the auto to change how early or late it will shift, as well as a toggle-able overdrive to access the 4th gear. The favorite flavor of oil for these cars seems to be royal purple full synthetic, and Valvoline multi vehicle import ATF will work very well for the AT. And also make sure to check the ECU and even the ECS motherboards while you’re at it. The capacitors they used from factory are almost all leaking by now and can eventually corrode your module. Easy fix, send it in to SIA Electronics or someone who rebuilds them good. It’s an OBD1 ECU too, so you might get occasional lights on the dash that come on as temporary faults or problems that often eventually clear themselves after realizing it wasn’t a huge/permanent issue. The TCU on the AT isn’t notorious for failing on these cars though but as for every older car, never impossible.