I'll knock £300 off for that lot

VVT is variable valve timing, on the st170 engine the vvt is on the inlet cam only and moves 60deg from 85deg btdc to 145deg btdc depending on various factor such as engine speed, throttle position etc.

When you change ecu it can be quite hard to map it unless you go for something like a DTA S60 which can alter the amount of degrees the VVT moves gradually, otherwise you can use a simple ecu such as megasquirt and it will come in at a fixed rpm.

I removed the VVT because the cams I received from piper specified fixed timings and I couldn't afford an ecu such as the S60. However you can still use the cams with VVT if you know what you're doing but you won't have 60deg movement, you'd have to restrict it to about 30 so in my eyes that isn't worth it. However, Catcams do some cams which have increased lift and duration but keep the full movement of the VVT.