Between Horton and Clowe I'd take Clowe. Horton's injury risk is too high for me to take him over Clowe. They are both good multi-cat guys, so they lose quite a bit of value in a points only league. The only thing separating them in my mind is their injury history.
I definitely wouldn't drop Briere for one of them though. My first drop would be Gagner, and if you're hellbent on taking Horton as well I'd drop Mueller. Gagner isn't going to get a sniff now that they've got so many great options in Edmonton. Mueller is a great sleeper, but his injury history is even worse than Horton's. I'd drop Gagner for Clowe and leave it at that.
16 team, full keeper
19 roster players, 15 prospects
Stats: G, A, PPG, SHG, special teams assists, SOG, FOW, PIM, hits, blocked shots, +/-, W, SO, saves, s%, GAA, shootout saves
C: Crosby, Backstrom, H. Sedin, Boyle, Brassard
W: Voracek, Burrows, McDonald, Filppula, Dorsett, Hudler, Abdelkader, Bouchard, Ott, Zuccarello, Stalberg
D: Karlsson, Letang, Enstrom, Boyle, Giordano, Gorges, M. Stuart
G: Quick, Kiprusoff, Ellis
Prospects: Granlund, Pirri, Caron, Killorn, T. Johnson, Galiev, Corrado, Vatanen, Moore, Rundblad, Bachman, C. Johnson, Desjardins