Reddit mentions of Performance Tool W32126 1/2-Inch Drive 30-Inch Breaker Bar, 1-Pack

It's not a terrible job. I just recently did this on my IS300 that also has the 2JZ-GE and you can do it in a day if you take your time.

You need to gauge your mechanical ability and tools-on-hand vs. taking it somewhere. If you can follow instructions and have some basic tools you can do this with the purchase of some extra.

Stuff you need:

• Balancer bolt comes off with this: http://www.amazon.com/gp/product/B0051XDBBG/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
  
• For leverage: http://www.amazon.com/gp/product/B00EP67SYQ/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
  
• Steering wheel/balancer puller (metric bolts)
  
• Timing belt tensioner
  
• Timing belt
  
• Water pump, bypass, gaskets, thermostat
  
• Serpentine belt
  
• Cam and crank seals are recommended
  
• Cam and crank seal puller
  
• Oil and oil filter
  
• Coolant hoses
  
• Coolant
  
  All parts minus fluids can be had for under $300 with good quality.
  Tools will be about $200 assuming you rent the torque wrench and puller.
  
  Expect at least 1 bolt to get stuck and/or stripped.
  
  You'll save a few hundred bucks but you need to weigh your time and ability vs taking it somewhere.