This looks like a cool kit, but you still need 4-5 other items from other vendors like the screen, dvi converter,raspberry pi, cables and board. It would be much better if the kit had everything you need for an install. I understand thats difficult and you'd have to stock these things, but shipping individual components will really add up for us USA customers and we won't be able to install it without all of the pieces. Plus the cost is variable where you get the additional items. $260 US is the base cost without the 5 items mentioned which would add another $150 US.
You've made great progress!
Quoted from DoctorPinball:
I just uploaded an Application Note for replacing Stern SAM system screens with an LCD panel - have a look at the document...http://www.drpinball.co.uk/docs/ApplicationNote3.pdf
...and a quick video of it in action with a white palette - sorry about the video quality...» YouTube video
The total price is less than £160 GBP, or $260.