http://www.trials-expert.com/#/maintenance-tutorials/4569661686
Shouldn't need a spacer just screw it straight on
EDIT: Apparently i'm wrong.. whoopsidaisies :$
Everyone's got different sized heads so what feels comfortable to other people may not be comfortable to you..
Your best bet is to get down to a bike shop and try some on..
It's an incredible line from Luke Cockshott...
sidehop up a wall and a couple of gaps then to floor...
This is a bit more streety but still pretty awesome
But in all seriousness... Do you ride with anyone with a hex? see if you can ride it a bit and make your decision after that...
This http://www.facebook.com/photo.php?v=10151287712262416&set=vb.260099184078567&type=2&theater
This is a perfect example of that..
Edit: not exactly perfect example... but shows TGS is still possible..