I think that you would be searching for some fairly depressing poems. You could try to find poems that accentuate the pursuit and "the chase" to which Willy is indelibly linked. Yet, I think that the end result of his efforts is where the poetry becomes most evident. One poem I would use would be Emily Dickinson's, "I'm Nobody! Who are You?" The poem is primarily about isolation and alienation and while Willy might not readily admit such descriptions about himself, I think that the poem speaks to his own predicament. The idea of being relegated to the periphery is something that Willy experiences, whether he wishes to admit it or not. Colerige's "Work Without Hope" speaks to a condition where one's fundamental notion of power and control are rapidly slipping away. The idea of "nectar in a sieve" might be applicable to Willy's loosening grasp on the world and his own lack of control over his own condition. At this point in time, I am partial to Auden's "The Shield of Achilles." I think that this poem can connect to Willy's predicament in a couple of ways. Auden wishes to tear the mask off of the Classical pursuit of war and reveal it to be a condition where there is savagery and only death as constants. In much the same light, Willy is shown to be a dreamer who is crushed by the weight of his dreams, inflicting pain on himself and those who have the curse of being around him. In both settings, a "de-romanticizing" must take place. In Auden's poem, Achilles' mother is horrified at what she sees on the shield, aware of what is going to happen and unable to do much about it. In much the same way, Linda watches what is happening to her husband, unable to do much about it, but knowing in her heart where the story will end.