if your looking for lot's of lite,,,take a old therm.pane sliding door pannel and place it sideway's over your work bench,,south facing is best for the low winter sun.
Insulation will be your best buddy,don't skimp on it,
Going fiberglass bats Steve...walls and roof! With the windows I want to install...should get some good residual heat from the winter sun through them.
Larry:
My shop is in my basement and I use this radiator thingie I bought at Wally Mart. Electric and I believe it is filled with some kind of oil. No open flame or element so it's radiant heat that heats the space and works great. My shop is about 10 by 15 so it's not a big space to heat.