[boxhead]

Hi there Ivan and welcome along.
There are many threads in the Australian section of this forum advising the pro's and cons of the different kits.
I am not sure where you live but getting a kit that is local to your area or state can make life easier.
You will also need to check with your local MVR-RTA-VicRoads (where ever you live) to see what emission levels you must meet, I.e what engine you can run.
You will also need to think about what your going to use th ecar for, as they are all different and some work better as circuit racers, some better as drag racers. If your just after a day to day or weekend cruiser then the decission will come down more to looks (as they are all slightly different)
If you can, go along to one of the club meetings, and dont be afraid to talk to people, you will find that most are very welcoming as we all share the same passion.
Also depending on your skill level will determine just how much of the car you can do yourself.
Most kits now are pretty good at being just straight up assembly when it comes to the mechanical side, I personally hate wiring, I did the engine and dash wiring myself, but could not bring myself to do the main harness through the car, ie lights, fuse panels etc, So I had this part done by an auto electrician.
Interior will depend on what your after and how "pretty" you want it, in my case I am chasing the circuit racer look so everything is very basic.
In any case I think just about every manufacturer has someone on here either building or driving one of there cars and if you ask a question, most people are more than willing to assist.