im about to invest in a bit of bitcoin as well as other cryptocurrencies such as eth, ltc, etc. Im thinking about making a wallet on a usb drive for a start. ive read about electrum but need something for all my crytpocurrencies.
I will suggest myetherwallet as it supports a lot of tokens. Other than ETH tokens, you have to see if the coin provide a offline wallet and what are the options in case of you want to store multiple coins in same wallet. I dont think many options are avaiable if you are looking for this type of online wallet.