Praise be to Allah.All Praise is due to Allah,
All Praise is due to Allah for having guided you to this path which you would not have been guided to without Allaahs Guidance. Your interest in embracing our religion is very pleasant news for us tonight. We pray to Allaah that you successfully embrace Islam and become steadfast on it.
As for your first question, if circumcision does not cause you harm, you can have it performed by a surgeon whos experience and skill you trust. If it would cause you harm, then you dont have to do it and that will not adversely affect your Islam, InShaa'a Allah (Allah Willing).
As for changing your name, note that the most beloved names to Allah are: Abdul-llah (The Slave/worshipper of Allah) and Abdul-Rahman (The Slave/worshipper of the Most Merciful one of the names of Allah). This came to us in the authentic Hadeeth (sayings) of the Prophet (Peace and Blessings of Allah be upon Him) which was narrated by Muslim (hadeeth number 3975).
If you want us to choose one of the names that you have listed, you can use Aasim which means: protector preserver defender guarder.
We pray to Allaah for you to have a Blissful and Pleasant life in the shadow of the Great Islam.