First time indoors, nutrients for hydro question

Gday everyone, im moving indoors for the first time and using a 1.2m x 1.2m x 2m tent with a 1000w light in an air cooled hood.
will be doing 9 plants in hempy buckets, im not used to using nutrients at all so i just have a few questions
Do i need a pH meter or ppm, or are they just helpful?
Can anyone recommend any nutrient brands? i was just going to go into the local hydro store and ask them
And do you recommend any extra additives on top of the base nutes?
This is the local hydro places website if it helps link should take you straight to nute section
http://www.greenacreshydroponics.net/apps/webstore/products/category/497712?page=1
otherwise i live in Australia and would use ebay as long as postage isnt ridiculous
thanks

you need ppm/ph meter, absolutely.

i like gh3, to label, prefer that over lucas.

superthrive, cal/mag, perhaps a pk booster for flower.

have a g'day, mate!