I'm in the "Uber" club. The seat components has been the only real issue with my bike. Here are my experiences on my stock Trek 7200:
After about 2,000 the plastic under the seat cracked. I (improperly) install a Brooks B-33
At about 3,500 my seatpost snapped. HOWEVER, I am very tall and had about 8" of the post exposed. Also, this was not a quality seatpost. I replaced it with A Thomson seatpost.
At 4,000 the rail on my Brooks B-33 sheared off at the seatclamp (Again, I improperly installed this in the first place).
I tried a gel "ass-hatchet" saddle for about 5 miles. No way!
I tried a "Cruiser" type saddle for about a week. It was ok, but started making terrible squeaking sounds from the plastic on leather construction.
I have finally settled on a Brooks B-67 (A single rail version of the B-66) Which is a medium wide saddle with springs-very comfortable.
So...I am currently just over 5,000 and have no complaints with the Thomsom seatpost and Brooks B-67 saddle.
I got the Thomson from Eric at Smart Bike Parts:
http://smartbikeparts.com/index.php?...&cat=Seatposts
I got the B-67 at Wallingford Bikes:
http://www.wallbike.com/B67.html
Both of these companies have outstanding customer service and return policies!
Good luck!