A B1 would be the correct visa to attend a conference. Check out their website. Often they have a link with an 'invitation letter' pointing out what the conference is about and how long it is going to last. You don't have to present at a conference in order to get a visa. Attending a conference is an entirely valid 'business reason' to come to the US.
Just please, please, don't do one thing: Come for the conference and then stay for 6 months to interview for residency positions. The goverment doesn't take kindly to these kind of stories.
I am not a lawyer. Whatever I write here is based on my experience, the experience of friends+family and my reading of USCIS memos, AAO decisions etc. It falls in the category of 'free advice', it is worth exactly as much as you paid for it. Before you make any decisions in immigration matters, please consult an expert in the field, and I hate to say it: That is probably an attorney.
hadron: a subatomic particle which experiences the strong nuclear force
hardon: just google it, will ya.