LINK G4X. But really the answer to your question should be another question. What do you want the ECU to be able to do? In the case of Haltech, they offer a range of ECUs from very basic all the way up to full on motorsport where the ECU can control a very complex motor but you end up paying for it. If you don't need all the control because lets face it, the 3SGTE is an 80s design, you don't need to spend so much to get the ECU you need. But the G4X will do what you need plus have room for more if you feel the need to add extra features the stock engine system didn't have.
You will need to add an intake temp sensor to the intake manifold but this removes the old AFM that isn't great anyway so win win!