Definitely keep it small. You will be 8 days from giving birth. A catered lunch at home is perfect. For both of our boys we just had immediate family and a few close friends -- a total of maybe 15-18 people. Keep the food simple. Traditionally it is bagels and lox, with tuna salad, egg salad, etc., and maybe a deli platter. Once you get in touch with a mohel s/he will be able to help you iron out the details. We used Rabbi Henesch both times, but he is not a pediatric urologist. It may be difficult to find one of those who is willing to take the time to come to your home, but perhaps there is someone out there who can do it.