The guy I emailed said 30 seconds or so, that he's done hundreds and been doing it a LONG time (I forget number of years), and that a topical anesthetic is totally an option. He doesn't use clamps or anything like that. I have yet to call and get the full details of how it's done...I was going to have DH do it honestly.
Take a deep breath. Given your description of where your discussion stands now, I fear both you and your DH have "lost the plot". The mechanics and specifics of how a circumcision could be done aren't the point, and should never be used as negotiating currency between the two of you.
Circumcision is a loss for life. You may or may not know it, or feel it, but I'm sure you know not to bring it up to your DH like that at this point. Topical anesthetic does next to nothing to help with the pain of ripping the synechia, and after it wears off (rapidly) your child still has a painful wound -- a wound susceptible to irritation, infection, and adhesion. It sounds like you, or at least your husband, is focused on the happy outcome 21 years from now when DH and DS can clink beers and say, "Heck yeah, like father like son!"
The point is, it will always be "like father, like son", thanks to DNA (and a happy upbringing). It's all in how he's willing to look at it. Instead of dwelling on a difference inside of their FTL, your DH can always look at your son and think, "Like father, like son, plus your mom and I gave you a lucky break I didn't get. You're my lucky boy."
Are you getting ideas? As others have said, wait a good while. Then, instead of focusing on the differences you both have, try nudging the discussion toward "based on my instincts after having DS1 and a lot I've been lucky to learn since then, I think -- no, I know -- we will both be happier if DS2 stays intact like the trend is in the US. What I would really like to talk with you about -- one of many areas where your thoughts mean so much to me -- is how we can someday let the boys know we made the absolute best decision for each of them with what we knew at the time."
[And if it helps, you can point out that intact has been the norm in the US for most of our country's history. Routine circ is a pretty recent fad when viewed in context. Probably neither of you has to look very far in your family tree to see you're only talking 1 or 2 generations out of hundreds -- so in the big picture, circ is not a family tradition, and letting DS2 connect with his roots is not far-fetched.]