No, dude, no!
If you are playing games and messing around with Workbench, get the A4000. You can do all that happily, and then one day if you find a PIV or an external scandoubler, you will have a super machine for your purposes. You don't need SCSI.
You can add a flicker fixer to an A4000.
You cannot add AGA to an A3000.
