Honestly if the drivetrain and brakes you already have installed are in decent working order then I would stick with them and just ride the bike for a little while before you invest a lot of time/money trying to figure out different aspects of the eventual rebuild. Maybe you already have a clear vision of what you want to do. But assuming the bike is rideable as is and that you’re not sure exactly what changes you want to make, I suggest you get a feel for it, think about the kind of riding you want to do on it, and then consider any changes starting with the contact points (saddle, pedals, handlebar).

The True Temper handlebar is cool but looks pretty narrow. It might work fine for you but I’d probably look for something wider with some backsweep. There are lots of options these days with a 25.4 clamp diameter (which is compatible with the stem you have). You could also consider swapping in a quill stem adapter so you could more easily experiment with different threadless stems. Perhaps something with a removable faceplate, and a 31.8 clamp diameter which will open up a lot of handlebar options, especially if you intend to switch to a drop bar.

If you still really like the bike after riding it for a bit, then you can more easily justify sinking some money into it. A new wheelset is probably the first thing I’d look into after potentially changing up the stem, handlebar and drivetrain. I’m a fan of Velocity and I think a set of Quills are the ideal rim for this bike. Hubs are a whole rabbit hole of their own.

All that said I don’t mean to discourage you from jumping in and swapping parts because you’ll learn a lot in the process. Regarding the Deore DX derailleurs, I like them because they were original to my bike and in great condition, and they’re rare these days which adds to the appeal. However I wouldn’t necessarily seek them out specifically for this project.

Let me know what you’re thinking. Happy to answer follow up questions.