I have used both Roll20 and Google Hangouts. Usually I use Hangouts since one regular player had a (Linux I believe) computer that didn't like Roll20's voice but handled hangouts fine. If no one objects to Hangouts I will likely default to it.
Wow you are very flexible. Starting Friday I can start a game any of those times as well.
Since you are the first response, did you have a favorite? Else I might wait a day to see if a second reply has a more narrow window. As the first response you could even decide you like Goblins, or another of the tier 1-2 evergreens better. I'd have enough time to prep.