I had a similar problem earlier in the year. I could down load any country except the UK just fine. UK would just hang. I even reset and rebuilt my iPad but still no joy.
I reset my home router to factory setting - but still no luck
in the end I noted that if I disabled my routers firewall, I could then down load UK.
I have no idea why other countries would load but for some reason my firewall blocked UK - its not as if I had any personal rules in the firewall - it was just factory standard stuff