If you are upgrading your set, I would suggest you need far fewer nickels, and probably fewer quarters. I run a full table 5¢/10¢ game with 100 nickels and 200 quarters. Once the group learned to make change efficiently, there were no issues. In fact, I fell like I could put 60 nickels on the table, and it would play just fine.
However, most of our pre flop opens are to 50¢ or more. Most bets post flop are in dollars. Your game may play smaller, but I doubt you'd have trouble with 100 nickels and 200 quarters.
The standard breakdown recommendation is 100/200/200/80/20, for a tidy 600 chips. If that's 5¢/25¢/$1/$5/$20, that would be be a bank of just over $1000. You can certainly get more chips, particularly the "workhorse" denominations, which would be 1's, maybe quarters if your game plays small, or, you could add more 5's and 20's to allow you to play larger stakes. But I'd be willing to bet the 600 chips would work just fine.
Decide your budget, then maybe expand it a bit, and you can get much better chips than the ones you mentioned. The cards molds ceramics have been extremely popular around here, and you could get 600 of those for around $250. Lot of microstakes sets are circulating.