Let me tell you something:
1.- You dont need programmers if you are trying to port the original Miiverse design into Juxt, its literally just CSS, you can just copy and paste the style on the Juxt CSS and mess with it. CSS isnt considered a programming language and its not complicated, its just a stylesheet anyway.
I also think a lot of people have access to arians Miiverse HTML dumps from back in the day, its not a big deal, most of the HTML, the entire CSS and JS were archived a lot of times anyway.
2.- I hope you mean “implementing this UI into Inkay” as changing the URL of the Miiverse portal to another one/your localhosted Juxt or anything, because again, Miiverse is entirely web based, its not an applet with like, moddable .bflyt/.anim files that you can mod, its entirely made of HTML, JS, CSS and server side logic.
The only “easy” way you can do a theme for this, is to set up Charles Proxy or your proxy of preference with your Wii U, add the Charles cert to the Inkay rootca for Miiverse (basically, rebuild Inkay but modifying the rootca adding your Charles one) and setting your proxy to locally load a CSS from your computer/other domain instead of the default CSS Juxt loads.
This is very complicated for a normal user, and even if you manage to do the theme successfully, i doubt anyone is going to do so much complicated stuff just for it.
What does this mean?
Making a theme for Juxt to look like OG Miiverse is very like possible, but dont expect it to look 1:1, Juxt changes some of the HTML structure from the original Miiverse HTML, and the CSS might have side effects, looking a bit off.
You can port the CSS from Miiverse HTML dumps and try to merge it with the current Juxt CSS, i just say from myself, its not going to look the exact same, very similar, sure, but not the same.
And even then, you still need a proxy and a rebuilt version of Inkay with the changes i mentioned before, i doubt the average user here is intersted in setting up all of that, as i said before, just for this theme.
Just wait for “rverse next” the new project from rverse, its not going to look exactly like Miiverse, but it might be somewhat promising.