The Cerbera Speed 12 race car uses the V12 engine from the original Speed 12 (now discontinued). In race form with air restrictors it put out around 600bhp. Unrestricted it's good for almost 900bhp. No top speed testing has been performed yet, so top end is actually unknown. It's only been in a wind tunnel recently.
No TVRs have been sold in the USA since the late eighties. There have been a few personal imports including one Cerbera, but that was recently smashed in a crash.
All the latest news regarding the cars can be found at
http://www.pistonheads.com/tvr