Look into the 96 to 99 models. Those are original 1kz. If you don't want auto, there are versions of it with 3l and 5l, those are economical and proper workhorses with no issues, and since they are manual, these are cheaper.
For starters, when going through adverts, look for ones with proper descriptions, next try to stya away from vehicles that are owned for less than 2 years.
Thirdly try to ask the owner technical questions, only technical people can run their vehicles well.