I am taking a working vacation in the U.S. for 3 weeks and thought Skype might be an inexpensive way to make prospect calls. I do not use an unlimited cell as I make all my calls on my land line at home.
I love Skype, but not for what you're talking about. You're limited to 50 different outbound phone numbers/day with their "unlimited" plan which can be a bit restrictive. I'm not sure what type of an internet connection you'll have, but that can make a huge impact as well.
If I was in your situation I'd consider using Vitelity or something similar. It's a bit more technical and tricky to set up, but I think it's a much more stable solution.
Since I just upgraded my droid software and skype software, it now works with videos. Don't use the skype moble version just the reg. one. Then turn it on in your settings.