Marvel -> DC Equivalent for this occassion

Using pre-Flashpoint heroes

Reed Richard (the scientific genius) -> Ray Palmer
Doctor Strange (the mystic) -> Doctor Fate
Iron Man (the common politically-minded man) -> Green Arrow
Namor (the anti-hero) -> Deadshot
Professor X (the metahuman community) -> Firestorm
Black Bolt (the extraterrestrial) -> Martian Manhunter

Using New 52 heroes (trickier)

Reed Richard (the scientific genius) -> Cyborg
Doctor Strange (the mystic) -> Zatanna
Iron Man (the common politically-minded man) -> Booster Gold
Namor (the anti-hero) -> Deathstroke
Professor X (the metahuman community) -> Flash
Black Bolt (the extraterrestrial) -> Martian Manhunter

• Vandal Savage
• Ra's Al Ghul
• Doctor Fate
• Hawkman
• Black Adam
• Phantom Stranger

While these don't fit your Marvel format, these are the characters I'd believe to be within DC's Illuminati. All of these are either immortal, centuries old, or have had multiple lives. These six I'd guarantee to be a part of it.

Batman: Humans.

Black Lightning: Metahumans.

Martian Manhunter: Aliens.

Aquaman: Atlantis.

Queen Hippolyta: Amazons of Themyscira.

Mr Miracle/Scott Free: New Goods.

Dr Fate/Kent Nelson: Magic.

• The Iron Man Role: The master of technology, represents the technological and industrial community. Also represents the type of hero that would work with the government.

Lex Luthor, I don't think any DC hero would fit this role better. Batman is too paranoid to work closely with The Government and dislike Cabals.

• The Namor Role: The anti-hero

Black Adam. Been around for centuries and doesn't mind getting dirty.

• The Mister Fantastic Role: The Scientific Intellect, represents science and the scientific community

Either Mr. Terrific or The Atom.

• The Professor X Role: represents the Meta-humans population and community

Flash(Barry) despite his goody two shoes pureness he was still part of the secret JL crew who lobotomized Dr Light.

• The Black Bolt Role: Represents Royalty and the neighboring Galactic community and population

Aquaman.

• The Doctor Strange Role: The Master of Magic, represents the mystical/magical community and population, as well as that edge of society.

Zatanna. Dr Fate is too powerful and untrustworthy.