I would suggest an option C:
server:1080/projectA/trunk/...
branches/branch1
branches/branch2
branches/branch3
tags/tag1/...
tags/tag2/...
server:1080/projectB/trunk/...
branches/branch1
branches/branch2
branches/branch3
tags/tag1/...
tags/tag2/...
I prefer to keep separate projects in separate repositories. Using svn:externals makes it easy to manage code library projects that are shared among two or more application projects.