Visiting the Sundarbans (Dhaka)

Hi everyone! I'll be in Bangladesh for business for a couple of weeks from late September and since I hope to have some days free, was thinking of visiting the Sundarbans to see the tigers. I've mislaid my Lonely Planet, though! So I was wondering if anyone from the local community could advise if it is practical to vist the Sundarbans in just three or four days, or is a longer time needed? And could you recommend the best way to make the visit, eg private tour, public tour, own arrangements etc? Thanks so much and best wishes, Joanna