PROS:
IMHO DENIZ URAL is one of the best and sells the best but his prices reflect it.
http://bestmeerschaums.homestead.com/coverpage.html
Meerqueen has a wider selection and a lot of affordable pipes.
http://www.meerschaumstore.com/
CONS:
Some of the Meer suppliers can be real asshats to deal with. Yavuz Körpefiliz / Storient pipes Would be #1 asshat.