I need to buy women's bike shorts with a chamois. I have only a 5 inch difference between my waist and hips, and my hips are pretty much straight up and down (waist 37, top of hips 42, bottom of hips 42). Also, I am tall, so I need a long rise. On any manufacturer's size chart I get a two-size difference depending on whether I choose to fit my waist or my hips. Which is the best way to go? Or should I compromise and buy a size in between?