have different vinum and grape series glasses for champagne, white, bordeaux and burgundy, basically covered what's needed as a minimum. whether to buy riedel glasses or other available in the market i think it's a matter of cost-benefit, but having the correct glass for the correct wine is the most essential.
i think all vinum glasses are made of lead crystal. it's the design of the glasses that has evolved throughout the years for the vinum series and therefore were given different series names.