1. Captain America- Brad Pitt
2. Iron Man- Johnny Depp
3. Thor- No specific actor in mind
4. Antman- Matthew McConnaghy
5. Wasp- Zihi Zhang
6. Scarlet Witch- Angelina Jolie
7. Quicksilver- James Haven (He was really basing this on their Sweet Home Alabama storyline)
8. Hawkeye- Bruce Wilis
9. Hulk- Steve Buscemi

Mark Millar's Ultimate Universe comics serves as main inspiration for early MCU storyline.
Mark Millar’s casting choices/references for The Ultimates (Avengers) from Marvel Spotlight (2005) #6