I've also had a trans sensor issue recently and ended up getting a built box from Justjap as I have plans for future mods down the track. I really can't talk highly enough of the service I received. It was bloody fantastic.
I emailed them on a Sunday and to my surprise got a reply. After many emails through the day and also into Sunday evening, I bit the bullet and went with a box they had built for Targa Tassie. Trans was shipped to Brisbane Monday and the car was ready yesterday.
I haven't had any dealing with Justjap in the past - and as mentioned I'm in Brisbane - but I will certainly be using them again in the future.
Also big thanks to CMR at Capalaba for their wonderful service.