Trade: Zbad, Wiercioch, prospect for Drouin
Sign: Stamkos (because why not)
I have Mac on the wrong side, but I think that line is competitive enough that they could cover that up, or he could be trade bait. There are a log of decent options for RWs in FA this off-season as well. Brouwer, Okposo, Stempniak are all available on the right side.
*Disclaimer* I do not believe the Sens will be signing Stamkos (and I know lots of you are wary about him), but you can't blame a guy for dreaming.