I'd get a Camaro if you are after LHD. The LS3 engine is spectacular. 
  
But......and I bet you knew I was gonna say this! 
  
£20k for a low milage excellent condition VXR8 with the LS3 engine. 
You get RHD, slushbox if you want one, 440bhp from a big daft V8, and lots of super saloon cool. 
  
Factor in £1200 for a custom exhaust with cut-outs like I had and you still have change from £30k 
  
With that, you could SC it with a Magnasun supercharger for £7k fitted.