Though i've listened much about 1kd engine issues,
i've been using 1kd Auto tranny in my prado 2006 since 2 years.
No issues of Injectors or soot so far. ODO is 84k+
And it gives 7.5km/l urban & 9km/l on highways.
i would suggest a 1kd if its available in your area.
Otherwise 1kz is the best option.