Should I apply for a Non-O retirement visa in Thailand or Laos?

The most important thing is always that depending on your local immigration office where you going to apply they might require the money to have been wired IE transferred from abroad which needs to be proven by the bank by your special statement that the money was coming from abroad...

If you're transferring the money the wise that would mean that you need to say that it's for Visa purposes.

But as always check the local requirements of your immigration office.

And you need to apply 3 weeks before the expiration of your current entry.

Since you already have bank account you can convert your tourist visa into non o and then retirement visa.

What's the problem applying inside Thailand if you have the cash and the bank account?

As Tod said, if you already have a Thai bank account you should be okay. It's probably a bit easier to get the non-O before coming, but you can still apply for the non-O in Thailand if you have a bank account already. Go to immigration when you get here and ask for their list of requirements for the non-O and deposit 800k into your account. Good luck.

pays to do research mate... you will overcome this little hurdle.. good luck

The reason that most people get Non-O visas from the thai consulate in their country before they come here is because it's getting harder and harder to open a bank account on a free stamp entry.

You said you already have a thai bank account so that's not an issue for you

You also most likely aren't entering on a "tourist visa" either and are just showing up 'free stamp' (60 day visa exempt) entry.

So get here, get the 60 days, get the 800K in the bank account and then when you have 3 weeks or so left on your current entry stamp GO apply for the in country 90 day Non-O visa (which you can do without having the funds seasoned at every immigration office BUT Jomtien). Pay the 2000baht, wait the 2 weeks under review period, go back get the Non-O visa and new 90 day stamp inked in

THEN

You wait until the funds are seasoned the 2 months and you have 30 days or less left on your new 90 day stamp and apply for the year extension for 1900baht. They issue that on the spot, after that buy a re-entry permit (1000baht single/3800baht multiple)and you're done..