What is this magical Quadra 800 with 520 MB ram you speak of???

In terms of choices I'm really just trying to get my greezy hands on anything 700,800,900, or 950. (I know the 840av rocks, but I wanna play with A/UX to astound and amaze my friends)

I have had experiences with the Q800/PM81/9100 incediable disinigrating cases. Had a one basically turn to ash upon dissassembly :-/