Not sure why you think you'll do better, money wise, going the route you
outlined for your conversion.  You may be 'buying' a bunch of headaches by
going that route..I dunno that for sure, but ...
  There seems to be available "standard" diesel-type conversion packages
available often, used, for very cheap money...I've seen a few for under
$500, then add the engine, which I often see for around $300 (gas 1.8liter,
complete)
  The "tried and true" Inline 4 conversion, at least you  would KNOW what
works, before you find yourself stuck with custom fabrications or
modifications to make an unforeseen piece-adaptation.
  I am not saying your plan is not a good one, or that you shouldn't give it
a go, but 're-inventing the wheel' usually ends up costing more in the end,
unless you are super lucky.  You mention you want to save money..keep your
eye out on the Samaba list and you'll soon see the whole conversion kit come
up, I bet...
  Good luck with it, I really like the 1.8 liter in my inline
conversion...Cheap, dead simple to work on, decent power and good
mileage...I did burn a quart of oil on my last trip...about 3000 miles
through the mountains..hee hee.  Dang expensive V W motor...
  Don Hanson