Even a fictional super spy has to have a cover story or "legend". I believe reason that in the novels Bond used a .25 Beretta 418 then a 7.65 Walther PPK was because those were commonly available civilian guns in Europe and if discovered might be explainable. A 1960s businessman (Universal Export) really concerned for self-defense might find an off-the-books .25 Beretta or a war trophy .32 Walther, but the latest gee-whizz-bang-special might raise some eyebrows higher.
Walther PPK might match the script and (some) publicity photos. The movie Dr. No refers to the Beretta taken from Bond as a .25 but the prop used was a .380 Beretta M1934. Both James Bond and Felix Lieter are supposed to carry PPK but the prop guns are Walther PP. When Bond needs to use a silencer, his "PPK" becomes a Browning 1910 (because they couldn't fit a silencer on the Walther prop gun). When Bond shoots at the "dragon" on Crab Key, he aims a Walther PP, it becomes a M1911 to fire blanks, then it switches back to a Walther PP. Come on, kids, the movie is supposed to be so exciting you don't notice these things.
But if you really want to match the movie, a 7.65Walther PP is the gun to look for not a PPK, but finding one that can transform into a Browning 1910 or a Colt M1911 and back to a Walther PP may be a problem.