I wouldn't recommend xapo.com - they require you to provide an ID number.
They don't ask ID for storing Bitcoins. If you do anything fiat related, ID will be asked. But as we don't have control over private keys and/or they don't provide some level of protection of lose, I depreciate using Xapo and Coinbase* and other such wallets.
* Coinbase introduced sort of paper wallet but I don't think it is secure to generate using the website. It is highly recommended to use BitAddress.org or Vanitygen or PC wallets to generate addresses.