My wife came home with a reusable cup from Starbucks the other day. It is a plastic version of the paper cups they normally use and it comes with a snap on lid, holds 16 ounces, 6.25" tall with lid, and weighs 1.6oz/44g. The barista said it can be used 30 times. It is marked number 5 plastic, BPA free and top rack dishwasher safe. They don't make a smaller version– a 12 ounce version would be great. The lid is much stronger than the typical plastic ones.
It begs to have a cozy. I have some EVA foam that might be good; otherwise, it might get a Reflectix tuxedo :)
Also, Starbucks will give you a dime off your coffee purchase each time you use the cup.

