Here's the new patch, with "Bytes" for display and size specification and some 
other improvements.

There's still something that could be seen as either a bug or a feature: Unless 
you specify the size of a partition in sectors, it is adjusted to whole 
cylinders. I don't know what the GNU cfdisk does if you specify a size that 
would cause a partition to end or begin in the middle of cylinder. I thought 
about a new command line parameter to switch off this security feature, but 
that'a something that requires a bit more thinking. Mark, would you need that?

Regards
Dirk