Yeh definantly get an inspection.... best thing to do is ask to take it to your mechanic.. or ask for an RACQ inspection - that'll give you a rough idea of the condition of the critical bits...
Even though i'm not personally a fan of the commodores - my old many had a VT II (his first commodore in a long while after owning people movers as we got to be a reasonably big family), and they go well.... reliable, enough grunt to tow a trailer to the dump should you ever need to and big and roomy for long drives... for a family car, can't go wrong really - especially given that you have the astina to turn into a crazy weekend car