Fannie Mae and Freddie Mac relied on customized big-ticket multifamily mortgage purchases to meet their affordable housing goals in 2003, but the Bush administration is still considering barring such deals in a new rule that will significantly raise the targets for the two firms. John Weicher, assistant secretary for housing at the Department of Housing and Urban Development, confirmed late last week that Fannie Mae and Freddie Mac met their funding targets for underserved borrowers…