I would go with the WALTHER P99 AS. It is a very well designed gun. I have shot both LUGER'S and the P-38 and while they work, they are not a smooth and ergonomic as the P99. Also, while you can collect and shoot LUGER'S, they are finicky on ammo and offer nothing to the shooter over the P99, which is also an excellent self defense gun for house or ccw.
The P-38 is more useful than the LUGER as it has a double action trigger, but again, it will be heavier, quite a bit if you buy one of the old steel framed guns.and the trigger will not be nearly as nice.
Good luck, whichever you choose.
Jim