I need recommendations concerning which clinic is the best for my fiance and her sons. I also need to know what I should expect to pay for the medical exams.

~ $100 US. Search through some of the old threads here for reviews, but any of them will work.

Despite what everyone says I think they are all the same. Price was our number one concern followed by closeness to any metro station.
Here is the list.
http://www.usembassy.ru/consular/consular....record_id=ivmed
We went with MOM or IOM as they call it now, because it satisfied both.

Last year the people at AO MEDITCINA were considered to be more caring. The price was a tad higher and the results were avaialble the following morning. The people at IOM (MOM then) were considered a bit less polite, the price was a few dollars cheaper and the results were available the afternoon of the exam.

People change so the caring part may not be the same.

MY NOW WIFE USED BOTH..
MOM WAS TERRIBLE...THEY GAVE HER A MAJOR MESS-AROUND...
SO THEY COULD GET MORE MONEY FOR MORE CHECK-UPS
MEDICINA WAS AWESOME AND FRIENDLY...
SO, PAY THE EXTRA MONEY AND GO TO MEDICINA

My wife used MOM for her K1 and we are 100% sure she will not use it for her CR1!

MOM staff went far out of their way to demean her unnecessarily. MOM has mistreated and abused other Russian fiances and spouses.