Travellers Cheques are really out of fashion now and a lot of hastle.
Foreign bank cheques (regardless of currency drawn) will often not be accepted due to high clearing costs. And indeed many places refused to accept any cheques at all these days any way.

ATM withdrawls will be the best way to get cash. Note the fees the cards may charge per foreign use, understand them. That way they will not be making small withdrawls many times, or using the card for low value transactions.

If you can get a card without fees on foreign use, even better.

Also, look at the reloadable 'cashpassport' style products, if you want a card that can be used for small txns. But you get these products aimed at different markets, you ideally want one with the fees hit hopefully only happening on the load, etc, not with each use. And hopefully acceptable fees.

If you are getting a card that you want to use for transactions, especially small ones, try to get one that has chip and pin. Plenty of automated ticket machines insist upon chip and pin these days.

For ATM withdraws, mag swipe only cards should be fine. But make sure you know your pin from the bank to use at the atm.

Either way, regardless of chip and pin or not, I'd want a credit card in my pocket as my emergency. And ideally a visa or mastercard network card, not just amex. Amex charges high clearing fees compared to the others, so some places don't take them, insist upon higher minium txn values for card use, or charge a small surcharge to take them.
Personally, I also always travel (actually, not just travel, live) with cards from multiple financial institutions, just in case any of them suddenly have a panic about where I am, and block cards, etc. The others wont be affected.

Don't want to alarm you. But some planning steps (practical ones: understanding fees, researching card products, having a backup card) can be much more valuable steps, than either a single perfect solution card (and just that) or travellers cheques, etc.


EDITED TO ADD: If using a card, either for cash withdrawls or purchases (debit or creidt card), you will often be asked if you want to use the machine/hotel/shop/banks rate for the currency conversion or you card network (visa/mc/amex) rate. ALWAYS take the card network rate, the shop/bank/hotel/machine rate will be poor - but it may be the 'default' option, that you need to change when doing the txn.