I spent the summer before last playing with new school hopped Pilsner type beers, loads of fun. My favorite grain bill was exactly what you have. Good call, as is your target bitterness range. And I did find that the slightly higher than standard Pilsner gravity you plan gives enough malt foundation for the more assertive hops. As for water, I found I prefer to keep the SO4 to 100ppm tops, probably lower, just way too mineral tasting beyond that with a lager fermentation, making the hoppiness seem a bit rough and unpleasant. Lager does need balance and elegance. Also, I recommend you try getting some or all of your bitterness from FWH with a new school dual use variety, to add some kettle hop flavor and aroma too. And FWIW, I love me a Simcoe Pilsner.