Going on vacation to San Diego and Disneyland. I am bringing my 5d mkiii with 24-105 and 50mm 1.4 and was just looking for something wider to 35 mm since I cannot afford the 35mm l. Any suggestions?
Neither. Use the 24 of the 24-105 for the wider end. You won't need a wider lens than 24mm most of the time. It's not worth carrying another lens to go to San Diego and Disneyland.
I certainnly love my 24-105mmL for walk around situations. For low light indoor use, the 35mm L is a favorite. The 40mm is, however destined to a lot of use if Canon's mirrorless body is small enough to carry in a pocket or purse.