If your money is held in a U.S. bank then the easiest way to get your hands on that cash while in Ecuador is through the use of an ATM. Most banks allow you to withdraw $500/day, though you should check with your bank to verify the limit. Sometimes the bank will allow $500/day per person not account, so you and your husband could potentially jointly withdraw $1000 each day.
Most appliance stores will take major credit cards. Just be sure to ask them for the “cash” price because that can be much lower than what is advertised. The advertised price often assumes you’ll be making monthly payments to the store and is therefore inflated.