So, I've other doubt about my next trip to SEA. It's not specifically visa related, but a "show me the money" issue at the border :D

If traveling around SEA, after some time in Lao and Cambodia, the plan is to come back to Thailand, spend just a few days (3-5) in the beach and then fly back home. As that will be at the very end of our trip, we won't carry 500€ in cash (we'd spent it by that time! :D)

In that scenery, should I show 20.000baths in cash when entering Tailand under visa exemption? what about under a SETV?

Is it mandatory to show cash, or can I show a bank receipt or inform with (more than) enough funds?

Is there any difference regarding the proof of funds when entering by plane or by land border?

My main concern is: OK, I can withdraw enough cash from an ATM at, i.e. Siem Reap, just before go to Thailand. But... what I need is THB or US$, so, how can I get THB or US$ while in Cambodia, if it's mandatory to show cash in the border? Can I just walk into a cambodian bank and get US$ over the counter?

If I need to show the cash, it's not a problem at all, it's not a matter of having money, but of have to carry so much cash - I wouldn't like to travel around SEA with 1.000€ in cash, just to be able to show 500€ when entering Thailand just for a few days...