How is it best to carry money in Peru.
Cash card, and few soles
Cash card, internet only 'cyber card', few soles, few dollars
I have to put money on the cyber card so I would top it up before I leave, but it does mean only having that cash available for online booking and purchases.
I live in Valencia, Spain so I have a spanish bank card from La Caixa, don't suppose they have a branch in Peru?
Assuming that 'cash card' refers to a debit card, that's the safest and easiest way to carry money. I never had any use for dollars, but other people will probably tell you otherwise. If you fly into Lima, there's no need to bring soles; you can make a withdrawal at the airport before doing anything else.
I don't know what a 'cyber card' is, but I suppose it's one of them semi-credit cards that you have to 'charge' with money from your checkings account. This type of thing may come in handy, but check whether the credit you put onto it is insured; if not, a regular credit card may be a better deal, depending on the fees charged by your bank.
Re La Caixa: afaik they don't have overseas offices. This is not a problem; the debit cards of most banks are either part of the VISA or Mastercard system, so you can use them in foreign ATMs of that type without problems. Also see the money matters article in the Travel Guide.