Engineer in the British sense or the American sense? I know a machinist from Scotland that calls himself an engineer. Caused me all sorts of confusion at first. He's only lived here for 20 years, I imagine he just does it out of stubbornness.

First off, I'm no expert, so most of this is just stuff I've picked up on forums. There aren't a lot of framebuilders left that build with aluminum. There are aluminum alloys that can be used after welding without heat treating (6005 maybe?), but I think they have fallen out of favor. So that's a downside. There are still aluminum bicycle frame tubes available for purchase. That's probably the best place to start if they meet your needs. Alibaba maybe? Chain stays are often made from straight tubes and bent/crimped. Very common on custom mountain bikes. You should be able to get a drawing of your cranks, that's where the real problems are if you are using fairly narrow tires.

I suggest drawing your bike in a 3d parametric cad program such as solidworks if it is available. I'm trying out Fusion 360.

Steel is so much easier to start with. I'm not sure how good of a welder you are, but the typical mechanical engineering student isn't much of a welder. Unless you are a machining student, in which case it is still probably true, only less so.

I know a builder that usually uses Ti. I asked him why he doesn't build in aluminum, and his reasoning is that Kinesis frames can be imported into the U.S. for about $25. And he didn't want to compete with someone that was selling frames for 1/6 of what he can buy tubes for. Ti is about the same difficulty and doesn't have to be heat treated, so that's what most custom builders use.

I'm not sure who produces Nova's aluminum tube sets. I assume it is Deda, but that's based on unreliable rumors.
http://www.cycle-frames.com/bicycle-...INUM-TUBESETS/
I assume they will ship.