Most places that do engraving can engrave glassware, or at least send it out to be engraved for you.
Most malls have a little store called "things remembered"....that's what they do.....sell and create keepsakes
Reidel spirit glasses are probably too thin to send to an engraver, however, they engrave their own glasses and I'm assuming a "special order" can get you exactly what you want right from the manufacturer.
If you purchase your own glasses to take for engraving.....a smart man would purchase and send a few extra's.....just incase they broke a few, or flawed a few in the process I'd also get a heavier type glass to do this.
As a side note, surely your bride has established a relationship with a bridal store. They do this kind of stuff on a send out basis too. But it'll cost you more money than doing it yourself!