Are there any DevC++ devpacks for the panda samples?

Not as far as I know.

… Are there cpp versions of the samples?

not as far as i know.
but there are some lines of the manuals available for c++

There’s a Roaming Ralph example in C++ at the forums. I believe some CMU ETC student was working on creating more C++ documentation, but I’m unsure if he created working sample programs.