I would want something simple, extensible, and easily readable. I would write in the clearest way possible in Bash with small, single purpose programs handling anything performance critical.
This makes me wonder if you might benefit from exploring more programming languages.
I've never found shell scripts (beyond the most trivial tasks) to be especially readable. Bourne-style shells in particular (e.g. bash) have a lot of easy-to-miss nuances that will lead to bugs if not carefully managed.
Hats off to you if you can do a good job of it, but it sounds to me like a recipe for pain when it comes to long-term maintenance.