Will any take US cards?
If so, what is the local ATM service charge?
After traveling the world using an ATM, we really don't want to bring traveler's checks and hassle with that.

I felt the same way, but was pleasantly surprised at how easy TC's were there, after not using them for years. Everyone seemed to take them, nobody asked for ID (you have to write on the back name, address, PP#), and there was no service charge or decrease in exchange rate where I went (even the desk at Banana Beach charged nothing to exchange for 2:1).
Never once used my ATM in a week.