Maybe a Scooter Skirt, or armored over pants for the legs.
The windguard you describe exists in a variety of shapes sizes and price points. Some have built on covers as well if ya poke around.
Here's a link that shows some of the range. Poke around a bit you may find better prices and more exactly what you want.
http://www.motorcycle-superstore.com/10980440/d/motorcycle-handguards (No endorsement for this site, they were bought recently and I haven't used them since..)
On my wife's bike I have some off-roading handguards & sometimes cover them with some mitts of the over the handlebar type you describe (see the peak link below)
I bought those over the years before some of the nicer ones that are made to work together came to be. If I were to do it over again I'd get the combo.
http://www.peakscooter.com/foulweather.html is the cheapest scooter skirts I've found. I have a review for 'em around this site somewhere.
I bought the skirt and the cheaper apron. I still have the apron since my wife uses it on occasion, but the HD didn't fit the skirt as well so I let it go with the S200.
I generally use my over-pants since they add a layer of protection as well.