advice on LDAP install

Hello
I have been assigned to move our NIS accounts to LDAP. I have used LDAP and NIS but I have never set them up.
This is my environment:

  • 5 Solaris 9 servers
  • 40 Solaris 10 Severs, many are zones
  • 8 Red Hat servers ( AS 4 & 5.5)
  • 10 to 20 users

Basically I want to set this up with as little money as possible. I'm not to knowledgeable abut this so I don't want to get in over my head.

I'm looking at OpenLDAP, ApacheDS and OpenDS right now. I looked into the Sun Directory sever and Oracle wants to much for it.(2k per processor) That's a bit much for only 20 users.

I'm looking for some advice, on what to do, or things to look out for.

Any help would be great thanks.