In Home Device version on new install

Following all the chaser e-mails from bulb I am finally thinking of jumping into the smart meatier, now V2 is the norm. As regards the In Home Device, does anyone know what version I would get, v3 or v6…or does it depend what the installer has available on the day?
(As I really want to be guaranteed a v6 one!)

I really wouldn’t bother. I have no faith in the smart meter readings which get submitted in advance (currently showing a meter reading for 1st December and sometimes it estimates as the darned thing doesn’t send readings) and the IHD is useless - current usage costs fluctuate wildly during the day.