Hey good to know that you have a D40 ,and i welcome you in this forum i hope you get many more information through this forum and small problems with vehicles are common not to worry about your diesel issues they can be resolved easily .
Hi Jon welcome to this forum well you want to purchase a new tires and wheels for your Navara ,so what type of wheels are you looking for ,are you looking for some standard wheels or alloys well if you could provide us with some more detailed information i think we can get some idea to help you...
So you have a problem with the steering rattle so did you try to fix the bolts tightly if not try that or you can just show this to a nearby mechanic he will get this fixed as it wont cost you much .
First i would like to welcome you in this forum and regarding your Navara 1989 model for which you are trying to purchase a wheel cylinder with push rods ,.yes you can pull the disc brake differently on it you will be able to fix it or you can take help from a mechanic he will help you get this...