Thanks everyone! We only have 1 Asian food market (or so I've heard!) around, and it's about 30 minutes from me. I'm going to try the McDonald's straws. Those are fatter and thicker than normal straws that you buy. I did try our party supply store, and they didn't have them...the guy I spoke with told me to go get some from the tea shop (like a cafe)! I'm going to order them from amazon, I think, and just have them on hand. I don't do a ton of stacked cakes, but they don't take up much room, so I'll go ahead and get them.
To the last poster: bubble tea straws are thicker, fatter straws that people use as supports in a stacked cake. I'm doing a 6" on top of an 8" for Sunday night (she changed the pick-up date!), so I think straws will be fine. If I was going to do something bigger, I'd most likely do something more stout, but I think they will be fine for this. You can google it, or look up "bubble tea straws" on amazon and see what it is.