Shiichan sucks and is written in PHP. Kareha sucks, is written in Perl (which causes more issues than anything else ever could when trying hard to do so) and doesn't scale well at all, seeing how a board of just the size of 4-ch needs to use archiving scripts in order to keep things running smoothly.
Have you considered <del>converting to Scientology and discovering what Lord Xenu wants for you</del> I mean Re-writing it in Rails?
Use textboard mode in TinyIB and edit CSS so it looks more like a traditional textboard.
Other than that you're absolutely fucked anon. Try making one yourself.
guys what do you think of weabot.py (what bienvenidoainternet uses)