I bought this top today. It fits perfectly and it's really thick as a cotton top.
http://www.jcrew.com/womens_feature/NewArrivals/knitsandtees/PRDOVR~18487/99102832455/ENE~1+2+3+22+4294967294+20~~~20+17+4294966973~90~~~~~~~/18487.jsp
http://www.jcrew.com/womens_feature/NewArrivals/knitsandtees/PRDOVR~18487/99102832455/ENE~1+2+3+22+4294967294+20~~~20+17+4294966973~90~~~~~~~/18487.jsp