This is just something that I thought would be interesting to pass along, in case you hadn’t come across it before. Baseball Think Factory calculates park factors for all of the minor league levels except rookie ball, both for 2007 and then a 3 year number as well, which is more accurate because of a larger sample. Park factors in general aren’t 100% reliable because of a number of factors, but they can give you a general idea in terms of which parks are very hitter friendly and which parks favor pitchers. The info can be found here.