I did the stock look myself, you can see
my work here.
3D printing good brackets for the ports sounds like an excellent idea. I also don't have a 3d printer, so I had to resort to spare parts I had laying around: nuts, washers, plastic washers, and aluminium tape to create the right fit.
You'll have to shorten the female connector in order to make them fit properly, as the iMac aluminium case will add a couple of mm between the connectors.
You can see how I did it in the link above.
I whole-heartily agree with you that you should avoid any drilling/sanding or anything like such as it will always look worse than stock.