For shortcrust pastry (ciasto kruche) the best is mąka krupczatka. But other types will be also OK. In Poland there is many different kinds of flour ("mąka") and they all are the plain flour. Different is the content of minerals (you will find on the package something called "typ" - the higher it is, the darker is the flour, whole-wheat flour is of the type of even 2000, while standard flour is something between 400 and 600) and grain size (krupczatka has bigger grains than the other types).
According to Wikipedia:
Flour that does not have a leavening agent is called plain or all-purpose flour.
So practically each flour sold in Poland will satisfy this condition. We don't have anything like flour with leavening agent. Or, at least, I haven't met anything like this in Polish shops. We just add baking powder or baking soda during the process of preparing a cake :)