<human>: Condense the text into a few key points

I have been networking and trying to get interviews with company A for 3 months. I finally got interviewed a month ago and they are scheduling me for a second round. I have been continually job hunting for the past 5 months. I recently was interviewed and offered a lesser position with company B but still decent pay and interesting enough. I told company A and they said they would try to speed up their interview process because they are very interested in me. They said the second round is more of a formality but it is with the department manager who has a final say (so could still say no). I am trying to negotiate an extension with company B to wait a week to give them an answer. If they put their foot down should I tell company B yes now and not tell them I'm going to continue interviewing and if company A says yes then reject B. Neither job will start before December. Company A is my first choice and are also giving me a strong impression that I am their first choice also.
<bot>: been unemployed, don't want to end up saying no and not getting another offer but also on the fence about misleading one company with the possibility of changing my mind.