I think CodeProject does have what you need: "A Resizable Graphical Rectangle" by Zebulon75018 [
^]. It's not "commercial control quality beautiful," but, it's quite well done, and very responsive.
I am using this with FrameWork 4.5.1 with no problems. However, when I downloaded the author's source code, it would not compile in Visual Studio 2013 after conversion: missing ResX file and one other file. But, it was easy enough just to copy the 'UserRect Class, paste it into a new Class in a new VS Project, and use it.
To add a 'DoubleClick EventHandler to it, just find the 'SetPictureBox method, and add the EventHandler to the 'mPictureBox variable. I assume you'd find it easy to integrate your current cropping code with this Control.