As Hugh said, stay with the original. I would only change springs if you need a lighter one, for using lower pressure target loads. But few Lugers are used for competitive shooting anymore. Once they were.
Potomac, huh? For 25 years I owned a home in the Bannockburn area of Bethesda, 7 miles from the White House and just a couple miles from you...right there smack in the middle of radical anti-firearms whacko land, home of Handgun Control Inc. and the Mike Barnes crowd.
...beautiful area.