I envy you... lol I do want a 265, but I dont see that dream coming true till my 3yr old is ready for college. Meanwhile I am building my car with the 4.0L. I have had a lot of different thoughts on the 265 fuel management. I believe that if I do go fuel injection, I am going to run the Jeep YJ for its simplicity. Coupled with the Fox Injection throttle body and injectors. They look like side draft webbers with 1 injector at the intake port.
As far as exhaust manifold, we have a shop near me who builds custom headers. He wont turn his machine on for under $2k. But he does good work. 3 yrs I could buy a built 265 hemi with new side drafts for just over $10K. Then add the other fabrication cost such as exhaust. With additional padding, I was guessing that endeavor would cost me about $17k to $18k. I will do that after I have the car mostly restored. May have to consider a second paint job when doing that which of course would add to the cost.
Needless to say, that dream is not lost. Just postponed.