If you're going to be in a business situation and you can get away from a suit, I'd recommend something in a Tropical blend form Jos A Bank (they're regularly on sale ~$80-$100). As the name would imply they're not all that warm but they're also not necessarily summer-only styles/patterns either (so some are). I have a light brown with a very faint blue plaid pattern to it that works very well as an odd jacket with either Navy or darker khaki slacks/chinos. I almost always travel with it on (with jeans) but when I do pack it (with the inverted fold shown in the video above) it comes out mostly wrinkle free and wearable, and a quick spritz on any problem spots with wrinkle release has it looking nearly perfect.

The patch pocket and zipper pocket would keep me from wearing the EB Voyager II in any business situation, but I would definitely consider it for a leisure travel situation where I needed to pack light but still dress for a wide variety of occasions (I'm envisioning an Anthony Bourdain type expedition for some reason).

I checked out Uniqlo about a month or so ago in NYC and I couldn't find the stretch jacket in the store, but I was NOT impressed with the quality of their other jackets (though their semi-stretch denim wasn't bad for the sale price). I kind of get the feeling that Uniqlo is the H&M of Japan.

I don't think you'll find anything in the sport coat category that's truly going to be stuffable and still come out wrinkle free or even wearable in a casual situation.