I work part time in the National Veterinary Research Institute here in Pulawy, and last year I mentioned to one of the professors that I miss eating lamb meat.
He phoned me the next day and said that if I came to his house he would have a surprise for me, and I went to his house the next day and he had found a 30 kilo lamb that he had just slaughtered and presented it to me saying it was a present.
After not having lamb for four years I was so happy and spent the next two months eating it.
One nervous thought occurred to me though was where he got it from, and whether it was a reject from one of the research projects that the institute does, but he reassured me that it was not.
The only region that I have seen sheep farmed intensively is as krysia says in the Zakopane region, and I have seen it on the menu of many Zakopane restaurants.
I guess if you are going to find it depending on where you located, is to try some of the butchers in the region.
My father-in-law used to farm them for the Italian market, and they used to take them at 15 to 20 kilos, but he stopped this 12 years ago, and I really don't know if this is still going on somewhere, but it's worth trying to find out.