Few queries FreeBSD upgrade

[KK CHN]

List,

I observe the following error while installing from ports collection
for any ports  in an old FreeBSD server

"/usr/ports/Mk/bsd.options.mk", line 90: Malformed conditional
(!defined(OPTIONS_DEFINE) || empty(OPTIONS_DEFINE:Monly)"))

I tried   the following

1) cvsup  and make index  throws  the following error

   Variable ALL_OPTIONS is recursive.
===> arabic/ae_fonts_mono failed
*** Error code 1
Unknown modifier 'u'



             2)   I done csup  -L2 portsupfile   && make fetchindex
  This also not helped

              3) portsnap extract && portsnap fetch update

  Nothing improved

All port installation fails, this is the port I am trying to install

star# cd /usr/ports/databases/postgresql84-server/
star# make install clean
"Makefile", line 115: Could not find bsd.port.options.mk
Unknown modifier 'u'

Unknown modifier 'u'

"/usr/ports/Mk/bsd.options.mk", line 90: Malformed conditional
(!defined(OPTIONS_DEFINE) || empty(OPTIONS_DEFINE:Monly)"))
Variable NO_OPTIONS is recursive.

star# uname -a
FreeBSD star.net 6.2-RELEASE FreeBSD 6.2-RELEASE #1: Thu May  5
15:55:38 IST 2011     root at star.net:/usr/obj/usr/src/sys/MYKERNELSTAR
i386

 I replaced the /usr/ports/Mk   directory with the Mk directory
downloaded from the FreeBSD-6.2 archive. Still the error in port
install  remains..


1) Is there any solution for  this issue other than   upgrade ?

2) Please guide me:

I must upgrade this  old release.   Can any one tell  me which order I
need to upgrade?

I mean from  6.2 Release to which next version and next  ?  please
mention the sequence  to reach 9.0 Release

3)  Which  upgrade method I have to follow ?     Source upgrade or
binary upgrade?

I am ready to do  source upgrade  please shed some light on  the pros
and cons of both ways of upgrade.

4) Which all are those system files & directories  I need to backup before
doing any of the upgrade to retrieve the system in case anything goes
wrong?

Thanks in advacne
krish