Wood is nice but I like the WWII OEM brown swirled style plastic that Walther offered until the late 60's or so.
Not sure if grips are interchangeable between the S&W and Walther but they have the Walther banner on them.
I found the website and its still up, historyarms.com will pretty much make any colour you desire for $45 bucks shipped and they make P38 copies as well.
I like the look of the white on stainless and brown on blued.
the reproduction bakelite P38 grips look like this