Eos can be bought on a lot of exchanges (I bought through binance on my last buy back as use this platform but there are many others) and can be stored on the exchange or as it was an ERC20 token it was stored in any ether wallet. Trezor have even allowed it which in my opinion it makes it a great endorsement. Also how it is a pair to tether! Now EOS mainnet has launched and the tokens changed the wallets will be coming soon. I know people using Scatter wallet but official wallet will be coming ASAP