Operating system recommendation

[pollex]

Hi, I want to know in your experience what is the best operating
system to run bind for an ISP. We currently have Debian for the 5
Cache servers and for the 2 Authoritative servers.
We have around 111851 success querys in the cache servers and around
7267 zones created in the authoritative servers.
We are doing a major re analysis for all the arquitecture and Debian
is changing to soon their versions and only have support for 1 version
before so I dont know if this is best option

Best regards and thanks