LOL hit something special. Apart from the fact that the LS1's which you make reference to were known to be piston slapping, oil guzzlers and mount tearing engines.... a 2 stroke lawnmower can get 300kw with enough displacement... while the inefficient pushrod gets 300kw out of a 6L engine other premium manufacterers get 400kw from similar displacement or 300kw with less (talking about Lexus F series here... more power, far more refined.... redline at like 8500RPM... try getting a pushrod that high freqently and see what happens!). Even Ford with a OHC engine get 300kw (Cobra and Orion no doubt) from a 5.4L. Power on a budget? Yes. Something special? HELL NO.
Personally Id go for the XR8, same price if not cheaper then SS or SSV (when spec'ed up)... a more sophisiticated engine, faaaar better transmission (ZF) and more reliable (VE has had 3 major recalls in short period). The only thing the Commodore has going for it is its handling, but its the difference between going through a Slalom course at 140km/h instead of 138km/h.. insignificant even on a track let alone public roads.