I'm not really sure to recommend something from that market. Nice piece of these products are lower brand (Rolnik for example). I'm surely can recommend a kielbasa slaska (especially grilled) and ogórki kwaszone [pickled cucumbers].

Don't even look on polish beer. Almost all of breweries was sold to SABMiller, Carlsberg etc. and now it taste like other commons internatonal "beer-alike" drinks. For now I can recommend only two, true polish-made beers: Zywe and Kozlak from small brewery Amber. It's very common in Pommern.