I should be purchasing a 2001 TJ executive wagon this week, its an auto with 110,000kms on it. I was wondering what sort of performance mods can be done to this car and where would be the best place to get parts from? I will probably be doing the Air filter and the exhausts first and was wondering what other stuff you could do before you go into the super/turbo charging route. I am in Tasmania and i need a wagon for my work

Welcome to the forum. My suggestion is:
Don't jump the gun. I bought the same, 2001 TJ sedan, auto with 111,000 km on it. I'm giving myself 6 months of normal use first. Before you start any mods, make sure the basics are done. Has it had regular services, and has the cam belt been changed? Spark plugs? Gear box? Does it need oil, filter, coolant, brake fluid changes? Tyres? How are the disc pads and drive shaft boots? I would check everything over to make sure its in good condition. No point sticking extractors, turbos etc on the car if the basics aren't sound. If it is going to be a work car it needs to be reliable and well serviced. Now if you wanted to build it into a show pony or weekend warrior, that would be different. lol