Use curve25519 for ElGamal crypto
Curve25519 was supposed to be mainly used for Diffie-Hellman key-exchange and it provides ~128bit security and should fulfill all standard security assumptions on elliptic curves (and even some more).

Now to answer the question is: yes.
ElGamal can be used securely with Curve25519, as ElGamal is simply a Diffie-Hellman key-exchange ($\delta= m*g^{\alpha k}$) using some message-specific private key $k$ which is transmitted via $\gamma = g^k$.This means one either has to break the Diffie-Hellman problem (which is hard on Curve25519) or break the discrete-logarithm problem on Curve25519, which is equally hard (as it would enable you to break the Diffie-Hellman problem)

However I'd strongly recommend against using plain (or even padded) ElGamal in production use. If you intend to use elliptic curves for message encryption and signature I strongly recommend you to either use EdDSA or ECIES.