In truth, as the others have pointed out, language is not important: you can work perfectly with your native language. However, there are undoubtable effects in the use of Nomina Barbara. Maybe it is just a psychological effect, but some words have a kind of potency, able to enhance a ritual. They call some connections, that your everyday words usually cannot offer. However, as Mycelial_Adept said ultimately you have the power, and utterances are just a symbolic manifestation of you inner potency.
Regarding your question, it depends on the paradigm you will use to perform the works. Old Norse/Old English is preferable if your operations will be related to Nordic/Germanic gods/entities. For Solomonic Magic (and some other Western traditions), Hebrew will be the optimal choice. I personally do not recommend Phoenician because: (i) pronunciation is not recorded (only consonants were written), so it has to be reconstructed; (ii) Phoenician records are scarce, so it lacks a lot of technical (and common) terms; and (iii) it has not got a living tradition for magical operations, you will have to create a lot of new stuff to work with it.