Hey guys I have an 06 Wrx that is soon due for a 100k service. Currently at 93k I was planning on doing it in 5000km a little early as I'm selling the car off. I plan to get a workshop to do the labour but sourcing the parts myself. Cos I work at super cheap auto, I get a pretty decent discount on everything we stock and can get from suppliers. Hence me trying to source myself.
Anyways I was just wandering what brands were good for the different parts i've listed below of the service , apart from oem which I will use happily if I can't justify an alternative.
Green means ill be using, Red means open for other suggestions, and ? Means no clue what to use, meaning please help haha.

Engine oil: royal purple 10w40
Oil filter: ryco
Fuel filter: ryco
Timing belt: Gates racing
Water pump:Bosch
Cam seals:?
Crank seal:?
Drive belts: Bosch
Idler pulley: ?
Tensioner and seals: ?
Gearbox oil: Royal purple what spec do i need?
Diff oil:Royal purple what spec do i need?
Spark plugs: ngk iridiums
Upper engine cleaner: ? The hell is that?
Brake fluid: Penrite orcastrol
P/s fluid:Penrite or castrol
Coolant: Tectaloy

So yeah hopefully im headed in the right direction if not please advise. Any and all helpis greatly appreciated.