Aussie Foxer

Hi guys, after just gaining a few new permissions here in Victoria Australia, i am in the process of shopping for my first centrefire. What caiber rifle would you have if you were limited to one? I have no experience of hand loading or shooting centrefires on a regular basis. I want to move up as i'm sick of the crafty sods hanging out at 150 yards plus. At the moment i'm using a .17HMR due to the size of my old permissions. This caliber has served me well i might add. Price isn't really an issue, buy once , cry once i say. I would prefer to stick to factory ammo. Any help would be much appreciated. Neil.