I bought all the parts from tyga (www.tygaperformance.com), cost about $180 aus each cylinder, and I did it myself. if you take your time and follow the rebuild instructions (don't worry about the bottom end part) in the workshop section you should be fine. the most complicated thing i had done before that was removing the carburettor from my 600 hornet and cleaning it. You could get them from bcomponents who are a tyga dealer based in melbourne

If you go to a workshop, you'll be up for several hours labour, plus they'd probably buy the parts from a honda dealer and charge you markup on that too. I was going to be ripped off because there's not many strokers in sydney, and the local mech won't touch them, but there's a lot more in melbourne being learner legal and all, so they may not charge as much