I did a lot of emulation, some is hazy in my mind now..
You speed will be limited by ECS and lack of enough 32bit ram, 8 MB is not enough to do run OS8 well, probably just enough to run 7.5. If you use third party video drivers they will give you speed but will chew up more of your RAM.
So I'd recommend: stick to System 7.1 or get more ram or use 4 colors or get a graphics card (this will make a huge difference). I know you want software config advice but really you need good hardware to emulate beyond just getting a screen up.
I once had OS8.1 with Microsoft Office for Mac and Netscape and internet explorer running on dial-up on an A1200 68040 with 32 MB ram in 256 colors dblntsc. The 256 colors slowed things down but it was very nice to look at. I then moved up to an A4000 68060 with CV64 and MacOS8.1. No complaints.
