From what I've heard, AOS3.9 is somewhat lagging on a machine without RTG. So you might want to take that one under consideration.
Retro_71: how did you manage to squeeze two HDDs and a CDROM into an A2000? One HDD and a CDROM is about it for me. I really would like to know, it would be nice to utilize the SCSI-controller in a more efficient way.
My system:
B2000, ROM 3.1
Blizzard 2040/40Mhz
Picasso II+
Scandoubler
Vlab Macrosystems digitizer (oh, how useful it is to digitize from VHS and such in the age of MPG, AVI and such

1Mb ChipRAM and 128Mb FastRAM
4.2 SCSI HDD
SCSI CDROM
Looking like mad for a Zorro-NIC. Would love to upgrade the Blizzard-card to 68060-standard. Considered expanding the amount of ChipMem to 2Mb

Running AOS3.9, and I've come to really enjoy that OS. But as noted, I'm not sure it would be quite as lovely without the Picasso-board.