Disklavier

I have converted quite a few midis from the internet using GNMIDI on
an old PC to use in  my pianodisc system.  I would like to use a  Mac
to
do this conversion, but have not found  any midi editting software
like  GNMIDI that
works on my  Mac OS X system.

I am trading in this current piano for a Mark IV disklavier system on
a brand new Yamaha  grand piano which has not arrived yet.  I know the
disks I  made for my  pianodisc system  (that work fine) will work in
my new
disklavier, but I  am wondering if  the procedure I   used in
converting these midis using 
GNMIDI options (edit  track to type in correct title,  convert to
Pianodisc, and format as 
type "0") are the best options to use.

It is my understanding that the  new Mark IV disklavier will  read 
format type "1" midis.  I  just wondered if that is true, and if in
the future whether it will
be necessary  for me to use  the convert to Pianodisc option.  I
believe
this option might still be  necessary to insure that the midi is in
track #1 and track #2.  
Am I thinking correctly?  

I just wanted to get a jump start in making some nice  midi disks for
my new piano as it  
may be another week or so before it gets here.  Ihave the original
downloaded (i.e. piano 
rolls, classical stuff)  piano  midis saved to CD's  right now and
will need to convert them 
to floppy or use the ones I  already made for the pianodisc system.  

Thanks for your help,
-Joan