To help the Polish genes thrive. :)
That is a very good idea.
Also seek for places that have huge Polish Diaspora. Since most of the Poles concentrated in one city, in some countries you can see cities that the majority of the Population have Polish Genes prevalence.
At the link below you can see those places. Currently the places where is easier to find polish genes outside Poland are Germany, USA (Illinois) and Brazil (Curitiba).
It is your right, as a receiver, to be able to define all the characteristics of the baby you want (including ethinicity).
(At least until now, maybe in the future Political Correctness dictatorship will not allow you that too).