It would help if you gave the error messages you are getting. Also going to http://groups.google.com and searching for "Perl Tk 64 bit compiling" gives some results from recent discussions on the newsgroup comp.lang.perl.tk about 64 bit on different platforms.

You also can get a 64 bit linux distribution which comes with pre-built Tk binaries, and get their source rpms, and see what patches they've applied to the Tk source, and the compilers. OpenSuSE usually does a good job of making sure everything works.