The Irish Ice Hockey Association tried this idea, before the league basically went defunct, with the "Latvian Hawks" -
http://en.wikipedia.org/wiki/Latvian_Hawks
No idea how it worked out, but considering the sorry state of that sport in Ireland in general, probably not too well.
I don't see such an idea working. I think you guys might be overestimating the size of the Polish community,
which as far as I know is on the decrease (I'm willing to be corrected on that if its not true), relative to the amount who would care about a football club built expressly for them.