I think what he's getting at is your better off building a forged 1.4L and boosting it up rather than spend all that on a 1.8 and hit the ceiling below 200HP
The question then becomes block strength, 1.8L block probably can't take the abuse the 1.4L...and plumbing has already been done by GM anyway and it looks stupid simple to pull these motors out.
F-body (firebird/camaro guys) take stock truck manifolds and put them "backwards" for front mount turbos and its actually pretty simple after some cutting and welding....
On my big build I went with a 408 cubic inch stroker motor (differant crank in a 6.0L LQ9-Esclade block), 12:1 compression big cam with internals ready for a big shot of Nitrous so I agree with the N/A motor ideas.
These little motors really do need the boost and forced induction to move the air for good HP/Torque motors in a drivable platform.