Refining On Corolla LE(AE80)

[sache]

I'm new here, but I got quite a bunch of problems. I'm using my father AE80 which is had few problem which I'm about to state. The car installed with Black Top 16V which is I need to replace some parts.

1st - About suspension. Which brand should I pick, the spring, absorber and rubber bush? I'm planning buying TRD Sports suspension but I think it too pricey and waste of tech using it coz I just using for touring from Terengganu to Kedah. Just to make sure it not skidding and hit the mud guard when entering corner. Plus should I used Spring Insulator coz I'm driving quite bumpy roads.

2nd - What kind of engine oil, gear oil and coolant should I replace? Right now im using shell semi synthetic 15/50 for the engine and donno the brand for gearbox and Toyota Coolant for radiator. I just found dealer for TRD that sell this things but I think I should wait to use the TRD stuff untill I get new BT 16V.

3rd - Is that true I need to change my plugs to Iridium Spark Plug for the engine and the spark plug cord? What brand should I choose?

I think that all the problem comes to my head right now. I hope someone can help me in any kind of way.