Let's try this in the correct forum.
Did a comparison of dimensions between the Ruger LC9 and P64 and found them to be very close.
Bought a DeSantis Apache ankle holster and it fit and worked great.
It didn't move unless I moved it and even with the Marshall grips you couldn't tell I was carrying. The only downside to Marshall grips that I have found, is how wide they are.
FYI, my jeans are pretty baggy. Slacks or tighter jeans might have given me away.
BTW, there is a site called Genitron that will will give you the dimensions of many different guns.
http://www.genitron.com/