I like the Halak/Kane side by a fair margin. Halak will get a few less starts likely than Varlamov, but STL is a win machine in comparison with COL. The G situation alone makes this savory, but getting Kane [who looks like PPG player this year] for an under-achieving Ovi [who right now we'd be thrilled if he even got to 65 points] makes this a steal for you.
More importantly it addresses a critical area of weakness on your roster...maybe 2 areas [if you count Ovi].
10 Team [keep 10 + 4 prospects]
Scoring F=1[g/a]; D=2[g], 1[a]; G=2[w], -1[L], 1[OT], 2[SO] Top 12 F, 6 D, 2 G count
Forwards
Crosby, Ovechkin, Backstrom, Wheeler, Byfuglien, Hornqvist, Simmonds, Ladd, Zuccarello, Ribeiro, Desharnais, Semin, MacArthur, Moulson, Purcell, Soderberg, Dupuis
Defense
Keith, Goligoski, Carlson, Krug, Trouba, Streit, Pouliot, Ceci, Nurse, Martinez
Goalie
Fleury/Price/Rask