Ok I thought I would add my two cents here...
Firstly my mate had diffculty finding Lee filters, he ended up going with a UK or USA company and it took like 2 months or more for them to get over there.
I saved enough money and had a look myself:
http://www.mediavision.com.au/
I think the digital starter pack (holder kit, adapter ring, Hard Grad and ND) cost me $443.85 AUD Delivered. Service was great and it took like 3 days for delivery (waited about 2 weeks for them to get stock) to Brisbane.
Ive been playing around so far with the Lee filters and they seem great so far...dont screw around with the colour etc.
One thing H... I know Ill eventually want to hand hold and dither with the Hard Grad... but how to you ensure there is no space between the front element and the filter whilst not bumping or moving the lens? Just practice holding your breath and work on the dexterity? haha
Say for example I was using my 24-70 @ 24mm as its reversed glass elements make it zoomed out @ 24 I keep doing my head in thinking I will push the lens back in thus adjusting the photo compostion? Does solving this problem just come with exp and practice because thats basically all I can conclude I just thought you might have some sneaky tips haha
Anyway hope the above link helps
Cheers