Hi PETEFLYS. Opening a bank account is a simple process, or completely impossible, depending on the attitude of the staff. I opened my Bangkok Bank account years ago, with just a 30 day stamp in my passport. As I understand it, many banks will insist that you have a Non-Immigrant visa before opening any account. As far as I'm concerned, some banks will waive the requirement, but you won't have access to internet banking, etc without the Non-Im Visa.
I'd suggest Bangkok large branches of the main banks, either Siam Commercial or Bangkok Bank. Thanachart bank has a large foreign ownership, which may or may not make them expat friendly.
Even if a Non-Im Visa is needed, at a few hundred dollars, you'll quickly recoup your outlay saving $5 per ATM withdrawl. As long as you use the branded ATM of your home bank, within the province, there will be no deposit, withdrawl, or monthly fees.