I could absolutely do Apple II & Apple /// Compatibility!

My only in-person memory of the the /// was that, circa 1981 or so, I went to a short-lived 'Computerland' store on the outskirts of town and they had one that they were too afraid to demo because they were afraid it would burn up. They sure were willing to demo the ][, I remember playing

https://en.wikipedia.org/wiki/Raster_Blaster

I was also planning to make a native version as you described -- But still keeping it hackable (using off the shelf and easily findable parts like the WDC 6502), but still keep it around below $60. (Still cheaper than ones on the market.. $300 - $400...)