I also agree with ditching the 50's. Two 25's do the job. You'll find most (not all) CT'ers are of this mindset.
The way I work out tournament breakdowns is:
1) Determine blind structure. This will show you your "workhorse" chip.
2) Determine starting stacks.
3) Determine rebuy stacks.
4) Arithmetic shows us what we need to color up. I color up two "jumps". i.e. to color 25's I figure it in 500's.
Here's mine:
T3000 w/rebuys *should* last about 8 hrs
basic structure:
15/30
25/50
40/80
50/100 (could do 60/120 but this is easier and gets us into 25's)
75/150
100/200
150/300 (end rebuys after this level)
200/400
200/400/25
300/600/25
400/800/50
500/1000/50
800/1600/100 (again, a rounding error to get rid of 25's)
1000/2000/100
1500/3000/100
2000/4000/200
3000/6000/300
... etc ... (now that we have everything in multiples of 100 it's easy)
Starting stack:
red - $5 * 10 = $50
green - $25 * 18 = $450
black - $100 * 20 = $2000
purple - $500 * 1 = $500
49 chips for $3000 leaving space for a bounty chip in 2x25 or half of a 4x25 chip box. One chip box = two starting stacks. Four chip boxes = full table of 8 players.
Rebuy stacks:
Here I have some leeway because my tournament set is faux clay and I have quite a few:
BUSTO stack (I think I have 8 of these, don't remember):
green - $25 * 16 = $400
black - $100 * 6 = $600
purple - $500 * 2 = $1000
blue - $1000 * 1 = $1000
Extra rebuy (rebuy anytime you have T3000 or less):
blue - $1000 *3 = $3000
Once the BUSTO boxes are gone, 6 purple get the job done.
Now, since I just have a lot of chips I didn't have to figure out how many rebuys I'd like to have, suffice it to say I have HUNDEREDS
Color up (max 24 players):
red - $50 * 24 = 1200 = 12 black chips
green - $450 * 24 + $400 * 8 = $14000 = 28 purple chips
black - $2000 * 24 + $600 * 8 = $52,800 = 53 blue chips
I also have 25 orange for $5000 and 10 gray for $25,000 (NERD!). Like I said, I have LOTS of rebuys, I can accommodate tables full of rebuy mania.
This isn't intended for you to copy directly (although that's fine, I don't mind) but instead it's to show the thought process and the math that will help you work out your perfect tournament set.
FWIW, I haven't played with this breakdown yet, I used to do a T5000 with blinds starting at 25/50. I added the $5 denomination because I thought there wasn't enough play during the rebuy period. I want lots of play (cheap flops) while the playin' is good. I want to encourage rebuys to get lots of chips on the table. mmmmm, chips.
GL and if you made it through this novel congratulations.