You only have the server dvd iso? Great, that is all you need.
Create a directory under /media named cdrom. Mount the iso like so: mount –o loop /path/to/iso / media/cdrom.
Create a .repo file under /etc/yum.repos.d. Give it any name you want. A good way to cheat is to copy the rhel-debuginfo.repo and make the below modifications:
Now you have a local repository that can resolve dependences. Issue a yum –y install cups-lpd* to get your required cups rpms.
Likewise, you can just navigate to /media/cdrom/Server and issue a ls cups*. Once you see your RPM file, do a rpm –Uvh cups-lpd . . . .