Have you read the "Ipseity" series by SkyIsGray? It involves a situation kiiind of like the one you described. Multiple Buckys (sorta), plenty of angst and trauma to go around, and with bonus excellently handled sci-fi psychology. (It's also honestly one of the BEST SERIES I'VE READ, so I highly recommend it!)

Link: http://archiveofourown.org/series/118750