Herrett's will make you a grip set that will fit your hand perfectly.
Gun stocks by Herrett's Stocks, Inc.
They have several styles.
Their Jordan Trooper is the largest.
Trooper Bill Jordan was a big man and one of the fastest, most accurate, point shooters to ever live.
He also wrote "No Second Place Winner" on defensive shooting.
I have 2 of these on N frame 44's and they are great.
The extra money for figured walnut is worth it IMHO.
One came back a little TOO big and they reworked the set for free to my satisfaction.
Good company.
I ended up finishing the set shown here with Dembart "London Oil" which is my favorite stock finish..
Another possibility but may be hard to find are the original S&W N frame smooth target grips from the 80's in Goncalo.
The Herretts might end up cheaper at the rate those old grips go for these days.