.5mm vs 1mm Oversize Pistons

[DieselScout]

They were leaning towards over sizing, but they added that it's probably "just" passable with old pistons and new rings if I can't find a new set of pistons.

Will oversize .5mm or 1mm have any noticeable increase in fuel economy?
Any additional power is just icing on the cake.

Wouldn't adding a turbo to a D24 NA require the following?
Exhaust manifold, turbo header, , turbo injection pump and injectors, turbo oil pan and oil cooler?
I've also read that adding a turbo to a D24 block can decrease the life of the engine compared to a D24T block?