John Donnelley's company GT3 Corporation - is on the brink of full production of his Mk III roadster. Cool car if you like convertible roadsters! John has history with Jaguar, Brabham Racing, Cobras and at least one original design that an example of is sitting in his shop.
John Hester's company GT Supercars - has a phenominal deal on his monocoque prototype. (See GT Supercars Monocoque thread under chassis for pics and more info. Also, I understand John will be putting updates on the Forum within hours.)
Holman Automotive - You are right Ron, it is not a replica. His cars are considered as originals by all of the vintage racing associations and are basically part for part interchangable with original Mk IIs (Big block, T44 and Tennant monocoque tub.)
Dan White, mentionded by Chip, also on the verge of production. Dan is an A&P (airframe and powerplant)licensed mechanic- skills that will no doubt lend themselves well to building a car.
ERA in the northeast has been around the longest. Nice product, top dollar, long waits.
American GT - never built the cars, rather OEMed them from Sabre which was John Donnelley's MkI name. They did OEM a lot of specialty stuff that carried the American GT logo for inclusion in the 351/G50 powered cars. Transaxles were beefed up by Patrick Racing. I understand that Chris Bramhall still has two of these cars.
[ July 15, 2002: Message edited by: Lynn Larsen ]