The fact that The Riches comes to mind when you think of Eddie Izzard tells me either you are young or you don't love him as much as you think.
He has been around a long time, and The Riches is one of his lesser accomplishments IMO. I know I am not that much older than you, but I remember watching his old stand up comedy.
He would make a good Binder, but I think he would also make a great Bob if the do a body form for him again.
I wouldn't mind Mark Sheppard as Binder. I only know Sheppard from Supernatural tho, which wasn't that much, like 3 or 4 eps I think.
I'm 25. I recall watching his stand up comedy as well, but I didn't think that the standup was quite the example of "morally corrupt degenerate" that I was quite going for (which is impressive, given that at the time, he was actively crossdressing). The Riches is fairly recent by standards, especially in Izzard's very long career, but it IS the most recent example that will resonate with younger people, as the show ran in 2008, and in that his character is the head of a family that stole another family's identity after inadvertently killing them in a car accident. And as long as he consults with Master Jim on Bob's voice, I'm all for it.
As for Mark Sheppard, he's had a fairly large career as well -- he usually only guest stars on shows, but his resume is ridiculously long. Watch some of his guest stints on Leverage -- he's originally an agent at an insurance company, portrayed as a foil to Tim Hutton's fantastic Nate Ford (the two are enemies in that his character, Jim Sterling, is originally Ford's rival at the insurance company they both worked at), and by the end of the second season, as an agent for Interpol, he's determined to bring Nate and his team to justice. He's delicious in the sense that you want to bludgeon him every time he pulls one over on another character, and yet you also want to fall on the floor laughing, because he's just so awesomely evil.
Mark Sheppard WikipediaI would also consider him for Marcone... if only he could rid himself of the accent