I just thought of something that might actually help, and you can play with this however you want.
I'm sure both of you have played some sort of mmorpg before and liked your character in it, right? So make your costume based on your mmo character!
That way you can keep your hair and glasses while still being able to dress up!
One mmo I think would be easy would be Ragnarok Online, which is known for its freedom with headgears and hairstyles. Glasses and long brown hair could be seen all over the place in the game. For low budget, make an easy class like Super Novice or high priestess. Ragnarok Online characters are pretty popular too, so you should be easily recongizible.
Of course, you don't have to limit yourself to Ragnarok Online. Any other mmo's you like will work too.
Hope this helped!
O another good idea might be Gaia Online, where you basically dress your character however you want. If you have Gaia online accounts you should know what I'm talking about. But of course for Gaia Online characters you might want to have a few items that are easily regonizible, like the sno yeti plushie or wing hair clips to show that you're from Gaia Online.