A good read-
https://www.speedsterowners.co...8#668422029750903678
If you need to read more use the search- there's been a lot more written here the last few years, but the above says it all.
Beverly Hills Motor Car has never 'built' cars- they seem to have an extensive inventory, as shown by their website, but further investigation will show that most (if not all) of those Speedsters don't exist on their showroom floor. What they will do (I think) is have one built to your liking, with the appropriate mark up. Now the issue is where will they have it built? Better to go to the source and have it done yourself without the middle man.
You were asking about the different builders- here's my take- While Vintage Speedsters in Arizona claims to have built the most Speedsters, most of those were built by the company when it was in CA and owned by Kirk and Mary. The present owner took over when Kirk retired (3? 4? years ago), moved the operation to Scottsdale, hired all new staff and from what we've seen here has had some 'growing pains'. Some of the cars we've heard about are not quite finished when delivered and needed some 'tweaking'.
Vintage Motor Cars (Hawaiian Gardens, CA) is in Vintage Speedster's location before the sale/move and features most of the old staff. All reports give Greg (the new owner) 2 thumbs up- he's easy to deal with and his cars are given a good shake down before they leave.
Intermeccanica (up here in Vancouver, British Columbia) builds an amazing car as well.