Hey aoneal. These mirrors are easilly broken of at the screws. As far as I know there is Not a brackeet kit. Are they power mirrors?
One of my GAs has had both broke several times, usually the car wash or my kids use it for gymnastics. LOL! What i did was drilled out the old bolt holes in the mirror, and put in dome headed bolts with the nuts inside. Dome head bolts look like these here
http://www.chaos.org.uk/~markt/scans/7m-dome-bolts.gif
Looks alittle tackey, but I saved myself alot. Dealers want to much for a newone over $100(for electric), junk yards might have one but the plastic , where they break, could hav unvisable cracks. Find a Auto Body shop and they'll usualy can get one for around $70-80, i think i paid $68 for a new one at the Body shop. I saw them on a web site too for around $80, but i can remember where they were. I'll PM you the link if I find it.