People buy Porsches, at least their first Porsche, because the car they see resonates with some vision of a 911 that they've carried with them, probably from childhood. For most people, that vision is a stock car. The stock car lets them imagine that they have been transported back in time to pick up the car they wanted. A modded car may have many practical and performance advantages over stock, but it just isn't what a lot of buyers have "in mind".
I sold this '87 coupe (50K miles, totally stock but with a partial repaint/accident repair) for $23000 through autotrader. The person who bought it was about 50 and he'd wanted a Porsche for 20 years.
I then bought this heavily modified '88 coupe with 40K miles (Fikses, Recaros, big red brakes, Wrightwood swaybars, big t-bars, strut bar, cat bypass) for $24K (owner asking $27K).
I sold all the go-fast bits for about $7K, and spent $2K to return the car to mostly stock shape, giving me what I wanted, which was a stock low-miles non-sunroof coupe for $19K.
I would suggest that ken_xman's best bet would be to return the car to stock, sell it for $19K or $20K, then sell off the pieces. The wheels, tires, and body pieces by themselves should bring in $4K to $5K, and selling a 50K mile G50 Targa in great shape for $20K should be a snap.