Not sure if/what he is up to now days but Nixon out of Zimbabwe has taken numerous bulls over the years in excess of 70lbs..with a couple over 80..

Hunted with him in 2004 and 2005 for buffalo--great guy and great crew..I do know once he started being successful his prices increased significantly...however, now that US citizens can no longer import ivory from Zim, his prices may have gone back to more realistic prices..??

I know another PH, Mark, works for Chifuti Safari's, also a very good PH..again, not cheap..
but you pay for quality I feel..

http://www.chifutisafaris.com/

Ripp