Wow Scott, do some research
$700 for a
set of JDM headlamps. And I did a full write up on how to align the stock USDM head lamps and corner lamps.
The S15 conversion would be a massive waste of money unless you have something to back it. Like the kid who did a full Skyline conversion on a Gen 3 with an Inline-4
And switching to a 4cyl? Where has this world gone
Maybe people don't realize how much money Justin (Wraith) has had to spend in order to get hit up to the point it is. It's not easy and not cheap.
I'd say stick with the 1mz man. It would be a huge waste of money to take on so many projects at once. And none of them would get completed if you are spreading the funds out.