Net Mgmt Tools and supporting OS

[vmalitani at gmail.com (vitto malitani)]

I am fairly new user of nanog mail list so I am not sure if the question
below is appropriate for this list.  If not, please excuse it.
- I am building a new low-budget customer WAN/LAN network and need some
ideas for network management tools.  I've seen couple of email threads
regarding all sort of "net goodies".  However, since I haven't used them
all, I am not sure which OS would be the most appropriate for these aps?
 Can anyone share their ideas in regards  of apps and supporting platforms?
 I would be most comfortable with free distribution of linux, but I am not
sure which distro supports most of the tools?  Is the paid OS required for
all these tools, like RedHat Server or SuSe or Windows platforms?

Thanks much,

Vitto