My preference goes the other way, but I think I'm the odd man out on a chip forum. Here's my thinking:
I think 160 1s and 160 5s is adequate for an 8-player table.
I think 320 1s and 320 5s is ample for the game, and more than that is overkill (two full stacks per player.)
My cash set has 160 1s, and I have a 10-player table. Even with a full table, we never feel "short" of singles, but I'd rather have 200. More than that is preference, not need.
Poker is a high-variance game. Whoever is swinging down will lose their playing chips, and then they will need change either out of the bank (cash change) or from the winners (check change). Adding more chips does not change the frequency of change; it just makes more stacks accumulate for the people having a winning night.
If that's what you and you players enjoy, winning stacks, that's fine - get more 5s - but in my experience, there are usually about two big winners on a given night, and they end up with a lot of stacks, and managing them usually turns into a hassle. This happens in a poker room because people keep walking up to the table with new chips, and if you want to simulate that, fine, but that's nothing special, to me. When we talk about big winners, we talk dollars, not stacks.
Then again, all my regulars are very comfortable seeing change come out of the pot, so we almost never have someone making change for a stack at the table. It really speeds up the game. In fact, it's pretty much only newbs that go asking for change. Even when someone calls a $2 PF bet with a $25 check, if the pot isn't looking to have enough change in it, one of their neighbors will break the $25 into $5s, usually before the betting gets to the big blind - and their other $3 will come out of the pot.
In my game the mentality is that whites are for blinds, reds are for bets, and greens are for winnings.
If I were you, I'd honestly go this set:
200 1s. ($200)
200 5s. ($1,000)
200 25s. ($5,000)
This covers 15.5 buy-ins at the $400 max. It covers thirty-one buy-ins at $200 (you will probably have more $100 and $200 buy-ins than $400s.)
If you want more head room, I'd add more 25s, not 5s. I'd remind that you get nearly as much headroom from a barrel of hundos as a rack of quarters, but I know you said 1, 5, 25 only. I don't get enough degenerates or marathon sessions to need that big a bank.
Here's how I'd buy them in:
$100 buy-in: 20 singles, $80 in 5s (16).
$200: 20 singles, $80 in 5s (16), $100 in $25s (4.) That's two even stacks of 20. You can prep as many 16/4 stacks as you have barrels of singles.
$400: 20 singles, $80 in 5s (16), $300 in $25s (8.)
Your first ten buy-ins get all of your singles in play, and 160 of your 200 5s. After that, avoid the temptation to buy in full barrels of 5s - instead, buy in with 25s and use the 5s for odd amounts (People buying $80 and $140 and what-not.)
If I were building this today, I'd stop at two racks of quarters, and get hundo plaques. And all of my players would want to be there the night a plaque goes into play because we have too many quarters on the table. I know some would bring extra cash, just to make it happen if we got close!