Owning it in a company will have GST & FBT issues. You can choose to depreciate the aircraft - or not. If you depreciate it, then you're likely to have CGT issues on sale. The company will almost certainly run at a loss. If there is some offsetting income you can put in the company it might work to advantage. Otherwise you'll end up with a tax loss you can't use. The decision about company or not will be determined by your tax circumstances. The company (in rough terms) will be $1k to set up and $1k pa to maintain.
In my opinion if you're going to fly IFR (especially single pilot IFR) you need to either own the aircraft it or know it intimately (ie fly a mates aeroplane). Single pilot IFR trips in rented aircraft is a mugs game. More so if its travelling for business.