i searched for a macro lens just last week and ended up buying the Tamron 180mm di for my canon 10D at $1250/- over at MScolor. Played and tested with it......works well for me. i need the long range and the macro for my work.
same price goes with the sigma 180mm too.
did try out the new sigma 150mm marco. priced at $1077 at MScolor. very sharp lens also.
you may try out the Tamron 90mm macro as well.