What's in hi-ratio and what it does:

http://www.fancyflours.com/hi-ratio-shortening.html

http://www.wilton.com/forums/messageview.cfm?catid=7&threadid=49726

(scroll to traditional American buttercreme)
http://www.pohlmanscakes.com/wedcakes.htm

What is angel white icing base:

www.sugarcraft.com/catalog/misc/icings.htm

Thread with another hi-ratio recipe:

http://cakecentral.com/cake-decorating-ftopict-19948-.html

Other hi-rato frosting recipes:

Brite White Frosting:

http://www.cakecentral.com/cake_recipe-2375-Brite-White-Buttercream-Icing.html

http://www.epicurious.com/recipes/recipe_views/views/109239

(scroll to basic buttercream)
http://www.cakewalkchicago.com/recipes.html

(scroll & look)
http://www.sweetcelebrations.us/Recipes/BUTTERCREAMS.htm

http://www.fancyflours.com/site/checkerboard-cake.html

http://cakemaven.com/forums/thread/163.aspx

http://www.onestopbaking.com/ipcms/recipe/Buttercream-frosting-recipe.html

LARGE quantity fudge type icing recipe:

http://www.mimacglaze.com/fudge_type_icing.htm

HTH

Thanks for helping and sharing Jan!! I really need to try the hi-ratio buttercream!