Hi All, thought I'd write a quick update. I spoke this arvo with a guy named Nick from Specialized Fabrications. I think they're over Narellan way, forgot to ask. Turns out these guys seem to do a one-stop shop, able to sort out my shaved door handles and the air-bag suspension height controllers, AND issue an engineering plate and blue slip for the car.
Some of the prices they quoted were a bit pricier than others, but some were cheaper too. And the convenience of getting all the work and engineering approval done in the one place is a big plus.
Just gotta get the freakin car in the country now....so excited I can hardly sleep haha!