Male Circumcision

I would like to know if circumcision (male) is a must for conversion. This is what the Prophet laid in hadith but considering the present scenario (if we hear the medical doctors) and as far as my feeling goes - how much is it necessary today? Can I have discussion with some teacher who is an authority on this subject?

Dear scholars, As-Salamu `alaykum. Islam talks about cleanliness. I am not circumcised, and I want to convert to Islam as soon as possible, at least before or right after Ramadan. I do not have the financial means to get the procedure done. Am I required to get circumcised before embracing Islam? Or am I supposed to do it at the time? I was told it is a very painful procedure. Please help me with this question. Jazakum Allah khayran.

As-Salamu `alaykum! I would like to know your view about the significance of male circumcision; I mean: is there any scientific value or medical benefit behind such operation? Jazakum Allahu Khayran.