Planning Kaitlynn's First Birthday Party

This week I started planning Kaitlynn's birthday party. We are inviting a pretty good size crowd because we only want to have one party. We are combining family and friends, adults and children. February is a very busy month for us. Dave's and my birthdays are in February and so are about 10 other family members' birthdays, plus Valentine's Day. We know for sure we are having it on February 23rd, because that is Kaitlynn's birthday and it is a Saturday. So my first concern was about where we were going to have the party. Our house is a little small to accommodate the number of people that we are inviting. I realize not everyone will come, but our house is not that big and I want everyone to be comfortable and the children to have things to do. I posted a few messages on some of the St. Louis mom boards I am on asking for suggestions of places to have the party. Some of the suggestions were the zoo, Museum of Transportation, Science Center, Carousel Room at Faust Park, YMCA, local rec center, and Incredible's Pizza. I looked into almost all of those places and either they weren't appropriate for the main age group or they were too pricey. I was finally thinking that I was just going to have to make it work at our house. Then my parents were talking to some people at a McDonald's and the people told them about this place that they are having their daughter's birthday at. It has a playland and so far looks perfect. We are going to have to talk to the place first to make sure it will work out, but I am feeling pretty good about it. So then I started on the guest list. Oh gosh, who to invite?!! I attend this Nursing Moms Group and am not sure who I should invite from there. There are a few moms (and babies and daddies) that I will definitely invite because I consider them friends. But for the rest of the group, I am not sure. There are a few moms that I talk to, but I would consider them acquaintances, not really friends. I don't want to invite someone and them think it's weird that I invited them or that I only invited them to get a gift for Kaitlynn. I also don't want to not invite someone and them expect to have been invited or get their feelings hurt that they didn't get invited. The group is also online (we have a web page with http://www.raisingthem.com/), so I don't know if I should just post an online invitation and just let them decide for themselves if they want to attend. I also have a few friends (not in the Nursing Moms Group) that I haven't really talked to in about a year. We have just emailed and sent each other Christmas cards. Should I invite them? I would love to invite them because I would like to see them and catch up in person, but again I don't want them to think I am only inviting them for a gift. I don't know why I am so worried about that gift thing, but I am. I need some help with this guest list, any suggestions or advice would be great.