On how to manage your money as you go.
Travellers Cheques
If you can find out whether there are or are not ATMs in all the countries you plan to visit, then I would consider the need for travellers cheques based on the answers you find there. It seems to me now that TCs are fast becoming a thing of the past and you'd probably only really need them if there were no ATMs in the country you were visiting.
Credit Cards and Debit Cards
However, you should consider the cost of using ATMs. They are usually not cheap. I was lucky in that another poster on here told me about a credit card (Australian) that had no fee for withdrawals and so I put my travel money on that card and withdrew it free from there as I went. It is your bank who does the charging not the bank in the country where you withdraw.
So I took two credit cards - that one and my original one which I would use for purchases. Its good to have a spare because sometimes one may not be accessible for some usually stupid reason. Make sure you tell your banks clearly that you will be travelling overseas. They should ask how long you will be away and where you are going, although if plans are flexible, let them know that too. Its very frustrating and time consuming trying to use your cards online to buy tickets when they won't work. As you are travelling in a couple, i would have one person carry one and the other person carry the other one in case of theft.
I had meant to have a direct debit set up to pay my credit card bill monthly, but i found out when i got home that these weren't set up. Luckily for me, it was a short trip and I didn't make many credit purchases with the card. So I recommend you sort this out early.
I would keep a good written record of your withdrawals and purchases and also make sure you can access your accounts online so you now what's left in the bank at any time.
Cash
I also took some cash ($500 for a four month trip). I never needed it but i had in case there was a hitch getting to an ATM.
A final point about security. There is a French traveller currently missing in India. The family are using his Atm transactions to help figure out his last known movements. So its not a bad idea to have your accounts sent to someone you trust to keep them in case you go missing. Unlikely i know but its not a bad idea.