If you haven't started building yet then you won't be able to go for the SVA
That is due to finish the end of April
You will have to go for the new IVA.
I cannot help you with that,
At the moment I don't think any one can help you as it has not been finalised.
All I can suggest is you take plenty of pictures whilst you are building
And get as many English receipts as you can.
This will help with getting your car registered.
Yes I have finished my car
Hope this helps