I don't get this approach at all. The ECU and FI setup are so vital to the health of your Z 
  
Why not just wait till its FI time? and get a complete bundle with a warranty .? 
How would you feel if you turned up a year after having you Haltech done 
to pickup your newly Fi'd zed. to be told "sorry, the haltech doesn't do the job properly!"? 
  
If you are planning to go the FI route,.... 
You HAVE to get both done at the same time, by the same tuner. 
No satisfaction, NO PAY! or a free return to stock  
  
We know the Haltech is good enough to support FI. If I can get a good price on the haltech fitted before I go FI then a bit more n/a power until I can go FI would be nice   
  
At the moment my main issue with going FI is finding an insurance company to cover me so a bit more power until then would be nice   
  
Ian mate,you are so right (along with Mark) on so many things! 
  
I just feel ( 11.5 months into my warranty period) that you can get into a real mess with this approach 
  
maybe best to have this conversation in Wales rather than on the forum....