In the end, you have to do what feels right for you. On this site, - and the world at large - there are a wide variety of people doing adotion in a wide variety of ways. You need to figure out what feel comfortable for you, what you are willing to do, and what you want. Then find a place for your child that fits. You will find prospective aparents that fit almost every possible description and comfort level.
Some thrive in the open adoption environment, some flounder and struggle with it. Some are much more open and involved than most. Many feel more comfortable with semi-open. Trust yourself. YOU are this child's mother, and YOU have the right and responsibility to choose what you think is right for him/her - and for your older child. I say follow your gut. (Of course, make sure it is an informed gut
LOL!) Trust your feelings.
(((HUGS!!!)))