I host similarly-sized tournaments, usually two tables. Do you anticipate rebuys? I only ask because you need to plan for them, but can also get away with fewer small-denom chips in the rebuy stacks.
For overall set design, if you really like to play wtih 5k-25k starting stacks, I wouldn't include T5 chips in the set. I'm sure you could find a way to use them (e.g., as antes in a T5000 stack tourney), but if your chipset is finite I wouldn't put resources toward them. I would stick to 25-100-500-1000-5000.
For a 5k tournament I would start with 8/8/4/2/0. That won't feel like a huge stack, and you could go 12/12/3/2/0 if you like more chips in play. But that requires a lot more T25 and T100 chips, which won't be as useful (if even in play at all) if you really also plan on playing T25k tournaments.
For 10k tournament I have settled on 8/8/4/7/0, with 5000 chips introduced later coloring up. In a T15k tourney I use this same stack but with a 5k chip to start. I used to use 8/8/6/6 for T10k, which is fine, but I found that once we get deep and short-handed we ended up with unnecessary stacks of T500 chips that aren't as useful when guys are betting in multiples of 1000. And as I mentioned above, if you play with rebuys you can stretch by using something like 4/4/3/3/1 for the rebuy stacks.
I think a T20000 or T25000 tourney might not use the T25 chips, but maybe you really want a super deep start with a 50/100 level. I would probably start with 0/10/4/7/3, or 8/8/4/7/3 if you do need the 25s.
Based on those stacks, if it were me I might structure the set like this:
25x160
100x200
500x140
1000x160
5000x100
That's 760 chips. If you wanted to make it an even 800 you could add a barrel each of 25 and 100. Having a full rack of 5k chips will give you a lot of flexibility and backup for tourneys in this range.