I'm assuming no rebuys
For T2000 if you want a decent structure that favors good players instead of just gabmblers you will need to start the blinds at 10-20 (or even 5-10 if you want more early play). I hate T5 chips so I would recommend you to make it a T5,000 or T10,000 tournament.
My favorite breakdown is (per player):
T5000
===========
12 x 25
12 x 100
3 x 500
2 x 1,000
Total chips in play = 2900
+ 100 additional T5000 chips for coloring up
T10,000
===========
12 x 25
12 x 100
5 x 500
6 x 1,000
Total chips in play = 3500
+ 200 additional T5000 chips for coloring up
You don't need additional T100 for coloring up the T25, just use a big stack player to get change for a few of the T5000 chips and use that change to color up the T25s. You'll be fine.
IMO this is a very cost-effective setup while still giving the players enough chips to be able to play without having to constantly be asking for change.
For 100 players and 6.5 hours I would recommend going with the T5000 tournament.
I made a quick off the top of my head blinds schedule for your situation.
Download it here:
http://users.onelinkpr.net/agc1976/p...0plyrT5000.xls
Hope it helps... keep in mind you have to add the breaks.