You don't screw with what gets you results. You keep both. Both guys combine with Harper and Zimmerman to form the offensive nucleus. You offer LaRoche a reasonable deal. He takes it or he's an idiot and we get the pick. He loves this town, look at the letter his parents sent to the WaPo last week. This team gets him back to the playoffs. He takes any reasonable deal. There is no reason not to.
Don't go losing one of your power bats just when things turn out sunny. Both.