I've never seen what you are looking for, and Nicaragua doesn't really produce its glassware (most of it is imported from Indonesia and/or Spain, as I recall) so you are up for a challenge. One idea would be to have the potters craft you something from clay - they could probably make a gorgeous beer stein for you. Start in San Juan del Oriente or the Masaya market and start asking questions.
Thanks for the link to the epinion. This guy loses one point for referring to "Nicos" and another for using the expression "O-M-G." I don't think the guy as much beer expert as much as he is beer lover, but his criticisms of the beer were pretty well though out with regard to bubble size, head, and grain processing. Damn them with faint praise, eh?
I thought this was pretty funny:
Usually, I can find some good beers just about anywhere, but in Nicaragua, that's a very difficult thing to do. I love the rugged beauty of the country and its shockingly sensual scenery, and if I do come back, it's for the raw beauty of the place --- it sure won't be for the beer.
Thanks for the great link - that was a lot of fun.