Looking for 3D Printer which meets certain Criteria

[Axel]

You could look at the Qidio iFast
From my experience having had three idex printers in the past, the second extruder was so rarely used that I now just have a single extruder printer.

The new Prusa XL looks interesting and probably fits your budget, but you would need to makle an enclosure.
Just realised that you said you need 820mm length, thats probably only possible with a belt printer in your budget.