They do look like high quality doors but 110,000 yen is over 1,000 USD plus you have to ship them overseas = $$$.
There is a guy out of Canada making fiberglass doors for $349.00 (US) each + shipping. www.showcars-bodyparts.com/
I think the GTR wheels look great other than the size. 16" wheels are too small for that car. You should be running 17 to 18" x 9.5 to 12" wheels on the rear of that beast. My plan for my 260Z is to have at least a 285 rear tire on 17 or 18" wheels.
Although I have never had a chick call me a "baby killer" I've had a quite a few females "flip out" over my driving habits. Most of them have said the ride was fun after they got out (kind of like a roller coaster on crack). I can't find a girl with the guts to ride with me in my 260Z, but none of them shy away from riding in my BMW...go figure.
$850.00 is not a bad price. I bought my 260z back in 1998 for $300.00 and a buddy of mine bought his 280z about 5 years ago for $750.00.
I have about $20,000.00 in my car and it still needs a paint job.
I have the same fiberglass bumpers on my 260z. I had to remove the stock bumper "shocks" and replace them with brackets that I made.
I couldn't justify the cost of factory brackets when the ones I made cost me about $5.00 plus a little fab time (approx. 1 hour).
If your car came with the shock mounted bumpers you will have to use the old style solid mounts. Mounting them should be pretty straight forward without any bracket modifications.
If you could post some pics of your issues I could probably be of more assistance.
Back in the day we used lead for body filler. No need to worry about bondo cracks and its not too difficult to use. The only problem is, lead is poisonous and hard to get. About the only readily available source is wheel weights.
Z specialties builds the connectors. The price has changed since I looked it up last. It is now 980.00 for the 70-74 and 1350.00 for the 75-78.
http://www.datsunstore.com/product_info.php/products_id/661
I'm working on building my own subframe connector for my 260z.
Not only will it be a lot cheaper but it will be much more functional than that $949.00 one.