With a 1 KZ, there's not much you can do that hasnt been discussed already. Although I would not suggest you to get a chip (effect on KZ is much less as compared to in KD hence chip is not very feasible). Performance intake is a good idea.
If the engine is not intercooled (1KZ-TE), would not recommend you to get intercooler installed from a local source as mechanics are like monkeys these days and might end u up much worse.
Good news is that KZ responds very nicely to nozzle (Injector) cleaning and refurbishment. Also, like a poster mentioned, diesel pump settings go a long way in improving performance.
In short, this is what i recommend:
Better Intake / Filters
Diesel Pump Caliberation
In order to keep it cost effective and minimize unnecessary fiddling, try these in the order mentioned above.