Yes, Pinot Grigio and Tokay Pinot Gris are great choices in addition to the ones you mentioned.
Billecart is a nice choice too but the inexepensive spumantes from Italy (like prosecco) and even Reisling Sekts or sparkling wiesserburgunders (if you can even find them at your wine store) are good alternatives to champagne.
In NYC Nancy's Wine is a good place to find all these great germanics. The buyer for that store, Willie Gluckstern, is one of the biggest experts on Germanics and really knows what he's importing.
Heres a list of wine styles from Nancy's site you might want to pair with grilled foods / summer cuisine
BURGERS, STEAKS, CHOPS: Rich, ripe reds with some sweetness Zinfandel
CHICKEN or TOFU: Light, aromatic whites -- Riesling Kabinett, Gruner Veltliner
VEGETABLES: Rich, herbal whites OR High acid, herbal reds -- New Zealand Sauvignon, Cabernet Franc, Beaujolais
SHELLFISH: Rich, dry, full flavored whites -- Loire Chenin Blanc, Tokay Pinot Gris
FISH: Full flavored whites OR High acid, fruity reds -- Riesling Spatlese, Pinot Noir Barbera
OTHER: High acid, fruity reds -- Beaujolais