catholic or presbyterian

So here I am two days away from joining FAPC (http://www.facp.org/). I've taken the new member classes and I've also read lots of information on reformation. I can honestly say that I'm protestant in nature (the philosophy behind questioning the bible and the Catholic church with its hundreds of traditions and politics, that hunger for understanding) although I was raised Catholic my maternal grandmother. I never had thought of signing up for membership of a church (building and congregation), but I feel at peace and at home (spiritual home, shelter). The concept of home is feeling good about being in a dwelling with others. Hence a spiritual home is where an individual may not only enjoy the companionship of others but also where the individual may grow spiritually. This whole experience has been strange, but now a question lingers. Am I Catholic as my grandmother brought me up or Presbyterian for the Sunday worship that I can enjoy and really be a part of?