So I have come to a decision on the direction my SW20 will be heading after looking at a large ammount of options, costs, and really thinking about where I want the car to end up.
When I get the money together(have started a seperate savings fund for this, not touching house savings) which will hopefully be mid next year to complete the entire thing.

Will be using a 2GR engine which means buying a wrecked/cut Aurion.
This I've been told should set me back 3-4k.
This will also be supplying me with the intended ECU and some wiring and other needed aspects.
Engine and Header Kit I've been referred to sits around 2k
Then I'll need to get an E153 Box and modify it to fit, as well as hubs/axles, thinking about 2.5k(I think)
Quaife LSD sitting about 1k.
I'm pretty pedantic and to me the exhaust has to have a Y pipe in it to keep it looking stock as it can be, and I'm also determined it has to be stainless steel, so another 1k-1.5k on the list.

The only thing I assume I'd need on top of this for an engineering certificate to pass would be brakes which I haven't decided on, but I was hoping to find something 4pot front and 2pot rear that will fit under 16" Enkei's.

If anyone with this conversion already done(and engineered) any advice or notes for the engineering regards brakes, or any advice or notes at all regarding the entirety of using the Aurion ECU would be amazingly appreciated.

If any of the prices whereabouts are off, or if I have missed something seemingly important, please let me know.
A big thankyou to Highlander for all the information, help, and patience thus far.

Terry at Road and Track does the 2GR conversion for 10k I believe. might be best to talk to him
 

my engine conversions can be approved for Qld or NSW but require the car to have the factory turbo brakes
 
any other brake conversion is a different matter. will require a full and separate engineering assessment and testing, if you just want to make up a "kit" out of bits and pieces you choose.
 
stock Aurion Australian spec ECU with immobilizers etc is used to allow 'simple" approval. I'm currently doing a Motec conversion on one but this complicates matters.
 
we typically buy a complete wrecked Aurion as there are lots of small bits you need.
 
we currently have 2 of these in progress and another sitting in the wings
 
phone me if you are interested in help from us
 

It is currently an NA. Would that raise the price?
Small ammount of research has shown that the turbo and N/A Mr2's have the same calipers.