Use of bitcoin client would be easier for him if all data expensive operations are done by third party client (for example my client) and his client would be able to verify found transactions and and them to his wallet.
that's what SPV clients, like electrum and multibit, does. they don't need you to download 70GB~ of data.
Of the two Electrum would be the best to get. It syncs light years ahead of the other clients and takes up minuscule amounts of space and bandwidth but there is a risk involved with using it as has already happened with the Doge electrum wallet.
If the BTC electrum servers get taken down or offline or whatever then those who use it run the risk of losing their coins unless they have their private keys saved for their coins.