[Jeroen]

The 944turbo and 964 C2 front calipers are the same ones
Those are NOT the 928 or 944 M030 calipers!

The conversion on the VCI site, is for use with bigger rotors (either 930 or 993 IIRC) which is why it is so expensive
For a 914 this is overkill IMHO

I have the 944turbo (or 964 C2) front calipers on my '87 911 carrera and I have NO fading on the track with them. And my car weighs quite a bit more than any 914!

So again, for the fronts, either redrill the calipers to fit the 3.5" mounting ears on the struts, or have the mountingears on the strut modified to the calipers

Mine simply have the calipers redrilled. That is the ONLY modification you need.
They will bolt to the strut without any spacers or adaptors and fit the carrera rotors
So it's about the simplest and cheapest brake conversion available and it works very well and is a very worthwile upgrade

Converting the C2 rears to mount to the 914 trailing arm may be quite a bit more of a challenge (the rears have 3" mount spacing on the 914 trailing arm)

I think the most seen rearbrake converion on the 914 is using the M front calipers with 911 vented rear rotors
I believe you'll need some very minor spacers to center the caliper over the rotor. So that is prolly the easiest (thus cheapest) option
Search the BBS on 'rear brake conversion' for further details, it's been discussed quite a few times already...

cheers,

Jeroen