ATMs & banking in Vietnam, Laos, Cambodia, Thailand

Hey all.

Looking for some useful information regarding ATMs and withdrawing cash through Southeast Asia. I'm currently in Ho Chi Minh City. I have 6 more weeks in Vietnam (motorbiking to Hanoi), then I'll cross over to Laos, and make my way through Laos, Cambodia, and Thailand for as long as I can make my money last.

I have a Canadian bank account (Scotiabank) that I have been withdrawing money from and although the fees aren't horrible, they're certainly not ideal. I was wondering if there are any international or southeast asian banks anyone would recommend getting an account with that would help minimize ATM fees and perhaps make it easier to withdraw money from?
I've been using Citibank ATMs in HCMC as I can withdraw the largest amount from them (6 million VND) at one time.

I've done quite a few Google searches and haven't come upon much (current) consistent ATM information regarding traveling through Southeast Asia.
If there isn't a bank you would recommend opening an account with, any information about the best ATMs to visit on my travels would also be very helpful! Keep in mind fees from my home bank per transaction - so the highest amount of money per withdrawal is ideal.
Also, I have a Scotiabank Visa card and an American Express that I would prefer to use for hostel bookings and travel expenses, if places actually accept Visa credit cards or AmEx.

Thanks in advance, enjoy your travels!