I use caxton FX, which one is better depends how much money and how you want to use it.
Caxton has a good app on the phone so you don’t have to log on to online banking or anything over dodgy wifi and lets you put any currency on it which is handy. Free withdrawals and usage out of the UK.
If you’re worried about that then best not to have a debit card at all, it’s probably just as likely to be stolen in the UK as Paris.
Never use my debit card for anything other than cash withdrawals at a bank machine i know is ok – everything else is credit card for security. CC charges are extortionate abroad so the FX card is loads better from that point of view, you can also fix your currency rate so you know exactly how much its costing without carrying around 000’s of foreign cash. A good foreign credit card can be good but even the cheapest will normally charge for a cash advance.