what size bike should I buy

[Owlie]

Specialized is nearby ish but Jamis is not. I plan on taking at least the specialized for a spin. I just have no idea what my perference is for materials.

That's what the test rides are for. Aluminum is light and cheap, but tends to transmit vibrations, though that depends partly on the quality of the tubing and (I get the impression) on the frame. Some people are more susceptible to it than others, and even then, you can minimize it by swapping some parts for carbon ones (if you choose to go that route) or even simply running a slightly lower tire pressure. Steel can be light too, and doesn't transmit vibration to the same extent because it flexes, though I imagine weight and ride quality depend on the tubing too. It's really a personal preference. The Coda looks like a nice bike. See if you can test one.