I'm not sure which is more or less expensive, but you can always throw on aftermarket EFI on that 427w if driveability is your concern. That may shift the balance of cost but probably not by too much. I may be against the grain here, but I'm currently refreshing a SBF stroker to replace a 32v 4.6 in my '65 Mustang so I'm not afraid to go "backwards". I will more than likely go with FiTech or something similar as opposed to a carb, but currently I'm not ruling anything out. Looking at your sig this won't be your daily driver, so I think it comes down to budget and personal preference

Also, I love the Eagles and enough of Joe Walsh's solo stuff...assuming your SN isn't just a coincidence.