I'm about to try my hand at raise paneled wainscoting in my dining room.

I've read a number of books on the subjects and have most of my
questions answered, but still have a few more.

The wainscoting will be painted white like the rest of the trim. In the
books I've been reading, they suggest that MDF works well for the
panels, but still use poplar for the rails & stiles. Is there any reason
I can't use MDF for the rails and stiles as well? This would keep
movement to essentially zero.

Secondly, what's the proper way to size the panels? The books have
suggested selecting a rail/stile width the same as the window/door trim
in the room. Given this, how do I establish a "standard" width for the
panels? There was an example in one of the books about the "golden mean"
for the rectangles, but I will still have to adjust some widths to get
them to fit in the walls. Obviously, I'll have to adjust some panel
heights to fit under the windows.

Thanks for any help.

~Mark.