Well, I placed my initial order for $1k worth of ETH today. I will use it as a springboard to buy other tokens. I would like to keep 1 ETH pocketed because I think ETH is going sky high soon. I may go over my investment by a few hundred by doing so, but I think it will pay off.
Lucky you, ETH is at a good buying place right now. Nice portfolio picks already but if you are worried about diversifying because of the wallet management problem then you could be better off (and safer) using a hardware wallet like Trezor or Ledger Nano. Having nice altcoins can really boost your BTC holdings. That being said, i would not bet everything on altcoins. I would bet some on bitcoin as well because I highly believe that altcoins would only achieve more success if bitcoin becomes more successful (mass adoption).