Any question answered...

http://www.moneysavingexpert.com/travel/cheap-travel-money

I use a caxton FX euro when I'm away, very simple to topup and then just use it like a regular card.

NH you just walk into a post office with your passport/drivers license and they top up and give it to you there and then (emma got one for chicago), the £750 limit is only for the first top-up in the post office as well.

No load fee over £500 and £5 below that, walk into the office in Oxford Circus to collect

https://www.thomasexchange.co.uk/currencycards.asp

Thanks everyone, I took on board what everyone said, but went for a Travelex anyway... I can pick up from Stratford so it's on the way home. Worked out OK. I'll post if I have any major issues, for future reference of course.