Intake Paint ?

Newbie here,
I'm planning to replace my spark plugs, and so I might as well paint the intake manifold while it's off.
Do I need to use High Temp paint? The reason I ask, is do to the limited color selection.

Also, I was planning to use Iridium spark plugs, mainly because they are less expensive than Platinum, wonder why?
Iridium vs Platinum?

Also, I pulled a plug today and it;s possible they're original from the factory, they are Platinum PFR5N-11.
I checked the gap...must be about .080". My 04 Tib GT still runs great with these old plugs and 74K miles.

Thanks, Swede