Serra/Sarraa' is a good name for girls. The meaning you mentioned is correct, and it is used twice in the Quran as you said. It is also the name of a sahabiyyah (female peer of the Prophet peace and blessings of Allah upon him), whose full name is Sarraa' al-Ghanawiyyah and who is a narrator of hadith.
The standard pronunciation of this name is [(SU)n + p(R)ay] + [(RA)ndom], but you can use the pronunciation you mentioned. It is common for people who speak non-Arabic languages to pronounce Arabic names differently from the standard Arabic, there is no issue with this.
Follow up question:
Sarra' binti Nabhan Al Ghanawiyyah, yes i find her. But where i can get information about her?
We looked in a sahabi database and found her entry. It appears that only two facts are known about her, the first is that she was a "head of household" before Islam, and the second is that she narrated the following hadith. The hadith she narrates is in Sahih al-Bukhari (Arabic wording here: http://www.sahaba.rasoolona.
com/takhreeg.aspx?ID=8793), below is a close translation of it:
The Prophet, peace and blessings of Allāh be on him, said, while at Minā: "Do you know what day is this?" They said, Allāh and His Messenger know best. He said . "This is a sacred day. Do you know what city is this?" They said, Allāh and His Messenger know best. He said, "Sacred city. Do you know what month is this?" They said, Allāh and His Messenger know best. He said: "Sacred month." Then he said: "Surely Allāh has made sacred to you your blood and your property and your honour as this day of yours is sacred in this month of yours in this city of yours."