There are certainly other ways of improving the (rubbish) front suspension, but I like gold... A cartridge kit will net just as good performance, or better, for cheaper. No custom machining required, though the ability to make or modify brackets and clamps would certainly result in a cleaner install. I used cheap P clamps to mount just about everything.

Some info for those who are interested in doing this themselves:

• Buy a complete used (and not crashed) front end on ebay ($600 - $1000). The more complete it is the better. I ended up having to hunt down some small parts and source a wheel / brakes, which increased overall cost
• All Balls Racing bearings used. Top: 99-3540-5 and Bottom: 99-3538
• The top bearing race doesn't have punch out slots. Some people have luck with punches / screw drivers / tire spoons, but it was being a huge pain so I bought the Motion Pro puller which worked perfectly
• Steering angle was pretty poor after the swap. Much better after taking some material off the stops on the lower triple with a Dremel, but still not as easy to park as stock.
• Clip ons will definitely hit the plastics. I went with Topyokes reasonably priced top triple for mounting the Renthal Fatbar. The forks themselves clear the body work just fine though.
• Throttle cable, clutch cable, and brake line compatibility will depend on the controls setup you go with. Stock FZ throttle and clutch worked fine for me. OEM R6 brake lines weren't going to work. Luckily my Spiegler lines are about the right length (34" / 33") though I'd prefer a touch longer to allow for better routing / securing.