Hi how much disk space take that etherum wallet after synch ?
I think it is around 13 to 15GB.
I use Parity, which is another Ethereum client that uses around 9.5GB of space. It is very good - I prefer it to Mist (i.e. Ethereum Wallet)
Alternatively you could use something like Exodus or Jaxx, which are light clients that do not require you to store the blockchain so have very low storage requirements.