My time zone is CET (Central European Time) but I can work in any time zone in the world. I really have no problem adjusting my working hours to any time zone in the world if that's required.
I prefer working and being paid on hourly basis or if I work on a fixed price-project some commitment to be made by the client such as 15% or 20% upfront payment. I will not work if there is no upfront payment or if we don't agree on terms that will satisfy both sides (this is with regards to fixed-price projects). Fixed-price projects seem to be tricky based on my experience hence I want both sides to feel safe, secure and happy.
Regarding communication I prefer email or Skype for negotiating the job or discussing project requirements; however, for project management I highly prefer that we use some project management tool such as: freedcamp.com, redbooth.com, smartsheets.com, jira.com etc.
Skype or email is not a good choice for project management in my opinion and based on my experience so far.