I made a list of items that I wanted my cobra to have and developed a very detail inspection check list/score sheet and bill-of-sale before I started searching for a cobra. It didn't matter to me how long it took me to find a Cobra that satisfied me and one that had a fair price that fit my budget. When calling about Cobras for sale, I used the inspection sheet to ask questions and took detail notes of each call. I used a 1/2 inch three ring binder to keep all my prospect cobras and notes organized.
I started searching for a Cobra late July and purchased my FFR Cobra last Sept. All I can suggest is take your time and do your home work. Make a list of prospect Cobras then call them. I sorted my down to 21 Cobras out of 100s and purchased the 5th one I inspected because it score very high. I flew to Florida to inspect the Cobra I purchased; the airfare was small investment compare to what I was spending. Again it didn't matter to me whether it took a month or a year.
Some Websites I used
427 Cobra Country--Ford AC Cobra replica manufacturers SUPER-SITE
CarsOnline.com: Shelby Cars For Sale
Good Luck...