She went Shimano Ultegra triple for her trike and Campag have systematically removed pretty much any reason to chose it over Shimano, so that isn't a problem anymore. I expect we'll end up at 105 or Ultegra level, which unfortunately means 11sp. Hydraulic disk brakes are a possibility but she is unconvinced about electronic shifting.
Threaded BBs are a must (no creaking) and we don't want dubiously reliable components like Specialized's Future Shock or orphan component standards. There is no need to stay under any arbitrary price limit but the cost:benefit ratio of Ti frames is unlikely to be justified.
We'll be fitting a dynohub wheel to whatever she gets and will use through axles with disk brakes. We'll almost certainly swap the LH crank for something 5mm shorter.