Hi mate I've got a Cheezy bar on my GQ and I'm a Tigerz11 dealer.
You need to space the winch back about 12mm and longer mount bolts, and over to passenger side about 25mm (which means redrilling the bolt holes and lengthening the fairlead and clutch lever slots on the passenger side on the bar) and it'll just fit.
It will look a bit odd not being centered but thats about the only way.
I wouldn't notch out the bar arm going to the chassis as it's an integral supporting member of the bar.
Is similar for most GQ bars with a 10K Tigerz.
Measurements here at the bottom of page: http://www.tigerz11.com.au/10000lbrecovery.html
Horses for courses really but for straight up fit the single speed 12,000lb, which is the next fastest after the 10K.
The 2sp 9K and 2sp 12K are actually a little slower than the 12K single speed because of their gearing.
Faster in 2nd gear of course but you cant winch in the 2nd gear, it's just for quicker rope release and retrieval under no load.
The 9K 2sp winch is 20mm shorter than the 10K so it will probably juuust fit with spacing back only and longer mount bolts.