I've moved through a few ircd's and settled on NgIRCd - a free open source server for Internet Relay Chat (IRC), which is being developed under the GNU General Public License (GPL). It has been written from scratch and is consequently, unlike most other IRC daemons, not based on the originator, the daemon of the IRCNet
- well arranged (lean) configuration file
- simple to build/install, configure and maintain
- supports IPv6 and SSL
- no problems with servers that have dynamic IP addresses
- freely available, modern, portable and tidy C-source
IRC bots / Hubot will connect to the IRCd as clients - they shouldn't be dependent on a particular IRCd
You can use anope to add a nickserv service through ngircd services - this is what you'll need to reserve nicknames.