Types of hardwood timber decking

You don't generally use hardwood for exterior decking.
Something like red oak is pretty impervious to insects, but it's prone to cracking and splinters.
Teak is about as close to hardwood as you'll get in a wood suitable for exterior decking.
But it's VERY expensive.
Mahogany, redwood and fir are better choices. The grain is tight and they take to temperature changes well.
I would suggest you re-think the hardwood idea