David,
Once a year Australian Classic Cars does a manufacturers listing of all Cobra makers in the country. There only a one paragraph description of each manufacturer or supplier, so there's not a lot of detail. I've found the best information is available through the Cobra Car Club of Australia monthly newsletter "Snaketales" It only cost about $45- for a years membership to the club, and the informatio you receive from there will more than pay for the cost of membership. If you didn't live so far away, you could get down to some of the monthly Sanctuary Cove breakfasts to see 20 or 30 Cobras / GT40s / Ultimas all in the one spot.
Which manufacturer are you leaning towards now, and are you thinking about a roller, or a basic kit? No hidden meanings behind the question, I'm just wondering how the decision process is going