Hi MontrealCL,
There is not that much difference between the Amiga 500s side expansion port and the Amiga 2000s Zorro II slots. In fact, you can make a Zorro II adaptor that will plug into your Amiga 500s side expansion port. This is what I did for my own Amiga 500 Tower of Power. It has a Zorro II connector and a CPU connector (slots), so I can use the same boards that are used in an Amiga 2000 Series computer in my Amiga 500 Tower. The best case to use is a large vintage case from about 12 to 15 years ago, the kind that use to cost about $350.00. These cases are very high quality and the Amiga 500 motherboard will fit better. I will put up pictures on Amiga Org soon of my own Amiga 500 Tower of Power. I first have to finish custom painting it. MontrealCL, keep in mind that I am a Class 4 electronics / mechanical assembler by trade, so I actually DO know what I am doing. Also, since I use to work for Commodore, before they went out of business, I DO know what I am talking about. If you want me to help you build an Amiga 500 Tower, the correct way, then let me know. You can email me. :-)