I have to second what bob said about Wells Fargo, not sure about B of A
BofA is nearly twice the size (by market cap~$200B) of WF, and both are enormous companies–more than an order of magnitude bigger than is countrywide, and none of these companies is as small and overextended as are the hedge funds or brokerages.
I’ll go out on a limb and say that if either closes up shop, I’ll eat my keyboard. (of course, if things get that bad, I may just have to anyway)