If Hitchcock were to be alive today, he would still: innovate and push the boundaries of cinema, gravitate towards suspense thrillers, and have a sense of humor.
Knowing all these things, I think for the DP (Cinematographer), he would work with Roger Deakins. Roger is british as well, and has worked on numerous thrillers and dark comedies with the Coen Bros. Among his best works include the Oscar-winning "No Country For Old Men" and more recently, "Sicario" which was Oscar-nominated and premiered at Cannes. Like Hitch, Roger has yet to win the Academy Award. In short, Roger is a great suspense-thriller DP that pushes boundaries and has all the big Hollywood resources to work on the the most cutting-edge sets in the industry. He'll even be lighting the new "Blade Runner Movie," a massive Hollywood sci-fi production. I can only imagine he has the chops to innovate alongside the master.
As for Production Designer, Hitch will probably work with Arthur Max at a certain point. Arthur worked on "Se7en," "The Martian" and "Gladiator," and has been nominated for the Oscars three times. He is capable of designing huge worlds that are grounded in realism. I know Hitchcock is not a fan of documentary realism, but for some reason, I feel that Hitch wouldn't use too much animation and CGI, because it's just too common in big-budget films these days. Hitch would probably find practical solutions to design, and Arthur Max seems to be the perfect guy for that: he builds big, lavish sets that are practically built rather than artificially designed by VFX. Not to mention, Arthur Max studied extensively in London, so there's that possible cultural connection too.
Music is tough. There's a saturation of film musicians, and no one person seems to be the defining voice of today's generation the way John Williams, or Bernard Hermann was back in the day. I see a lot of posts favoring Hans Zimmer, but I digress--Hermann was not the Hans Zimmer of his day, not that he has to be, but Hitch seems to favor a special type of musician that engages in diverse experimentation of style and content. Hans is prolific and his music is strong and big, but it's not the kind of projects Hitch would probably direct all the time. I bet Hitchcock would rather go with Alexandre Desplat. He has tons of awards, and even won the Oscar for "The Grand Budapest Hotel." He works on Hollywood big budget movies like "Harry Potter" and "Godzilla," and award winning indies. If he doesn't win awards, he works on projects that do, such as "The King's Speech," "Argo," and "The Curious Case of Benjamin Button." Hitchcock is a prolific director, and his musicians seem to be equally so, if not more prolific in their respective field. Alexandre probably has the versatile skill sets necessary to work on a huge variety of Hitchcock pictures.
As for writers--Hitch seems to love working with authors of thriller books too. Gillian Flynn did "Gone Girl" and "Dark Places," both crime thrillers that have been adapted into feature films. But I feel like Hitch would probably option the rights to another one of her books. It'd be interesting to see what he'd pick as a source material.
I can't really think of any other collaborators at the moment.