I would go with usps, they are normally pretty fair. I have heard too many bad things about UPS so I have never used them myself. My packages usually take about a week and a half to get to me.
With USPS you might get hit with custom fees when they get to your door. Mostly you don't but sometimes yes. With UPS, they hit you with their brokerage fees every time they knock on your door. That's why I always prefer USPS.