Could be worth looking into
Rust, it's got a few good properties for a project like this: fast and pretty high-level to develop in, fast execution with low-level access to the system, lots and lots of built-in safety measures to avoid programming mistakes.
Possible drawback is that the devs do not (yet) know Rust, but it is a really good fit for this kind of project and would be well worth 10 minutes to check up on?
Anywho, good luck with this project!
Sure, Rust is one of possible candidates for some alt clients. The same applies to other contenders to a title of modern programming language around.
But there are reasons to be conservative in approach. It's useless to initiate flame war here, so I suppose it's better to say that hipsters' toys become really useful when said hipsters see their first machines in museums and grow beer bellies.
By the above I'm not saying that these languages suck - every language do, just in different areas. I appreciate Rust's features; played a little with it. And I even like it.
So, to sum it up - yep, Rust is welcome if there will be someone to write alt implementation based on the reference one.