I personally think the single din looks better , it just fits the early 986/996 better no offense to those that have done double din installs . Here is my good/better/best suggestions.
1. Continental with or without CD player . It has Bluetooth and a background orange color that closely matches the Porsche. Price around $180.00 + or - .
2. Blaupunkt has several models ranging in price from $250.00 to $500.00 or so . Also period correct looking .
3. Porsche classic ........... bring wallet
I am not an audiophile so take what I said as my opinions . I based my opinions via online reviews on several Porsche forums . My 996 purchased used doesn't have a radio , but I will be adding a single din in the future .