The reason you trade Clippard is because he isn't the best bullpen arm the Nats have and he also doesn't have the best stuff, just a really quirky delivery. He had a bad year from the All-Star break on forward and I'm convinced by this point that Garcia or Mattheus are better options as 8th inning guys.
Clippard and Morse will not net as big of a haul as people think they will. As fans we all tend to overrate our players, but to be honest we have a great Set-Up man with a wonky delivery and a good change-up who has let the ball fly out of the park a few times and a great hitter who hits to all fields, tends to have a high K rate, and isn't mobile enough to be a plus defender at any one position except for maybe first base.
The Nats will not use Morse at 1st as long as LaRoche plays here, and unless you are Slate, Moore can be a potential Morse like bat at a younger age. Clippard also has a handful of other relievers who may be better suited to setting up Storen. I think the smartest thing is to dangle them to see what you get for them (no one is trading them to get an MLB piece back like a stud CF who can lead off or a Trevor Rosenthal) and fill positions with some guys within the organization and the potential FA signing.
2012 Nats gone in 2013 - Morse LF, Clippard SU, Mike Gonzalez LHP, DeRosa U, Flores C, Lannan LHP, Jackson RHP.
2013 Nats not on team in 2012 - Madson RHP, B.J. Upton CF, Greinke RHP.