Also if I was to turn this into a 500 piece chip set what would you guys recommend for the next 100 chips?
It looks like you were planning 10 stacks of 12/12/3/7 with your current breakdown.
You could change to 12/12/5/6 by adding one more barrel of T500s, but I wouldn't add any more than that.
If you are considering T20000, you would do either 12/12/3/7/2 or 12/12/3/12/1.
To do the latter you need to add 60 * T1000, and then 40 * T5000 would be helpful to cover the larger re-entries.
You could also add 20 * T500, 60*T1000, 20 * T5000 for 100 chips, that would give you 10 stacks of 12/12/5/11/1.
At base T25, I really don't think T25K chips are necessary unless we are talking about a larger multi-table set. (Think about it T25K * 20 chips is T500K, you will never be in a siutation where you would want your whole tournament represented by 20 chips, and that's 25 entries at T20K as it is, really only consider T25K chips when we are talking closer to T1M in play, I would suspect that's about a 4-table minimum.)
So to summarize, I think increasing capability to T20K is a good use for the "next 100" chips, and these two options accomplish that.
1) 60 * T1000, and then 40 * T5000 (Yields 10 T20K stacks of 12/12/3/12/1)
2) 20 * T500, 60*T1000, 20 * T5000 (Yields 10 T20K stacks of 12/12/5/11/1)
Just comes down to your preference of 3 or 5 T500 in your starting stack.