Moments after he delivered a eulogy for the three U.S. diplomats killed last weekend in Bosnia, President Clinton named a new team to try to regainprecious momentum toward a peace agreement. The new lead negotiator is Washington lawyer Roberts Owen, who has worked for Clinton in the region before. Washington correspondent Douglas Waller says the diplomats died just they were making headway with a new U.S. peace plan for the Balkans. "This was the team that was carrying the water; they were the real worker bees doing work of ironing out the details for this plan." The toughest sell now, Waller says, will be a meeting next week in Paris, where Owen must convince Bosnian President Alija Izetbegovic to cede the prozed Gorazde enclave to the Serbs.THE "NO EXCUSES" CANDIDATE?