Yep, I would go hardwood or composite if you are planning on keeping it any length of time.
In terms of the frame, are you concreting the posts into the ground? If so I would think about what wood you are using there, as standard 4x4 posts will rot out faster than anything else, you can slow that down a fair amount by using post savers or slow it even further by using a harder wood for the posts. I used 8x4 oak sleepers ripped in half, and then put post savers on as well for double protection.
I think we are going to make concrete pads and bolt posts on them. We've had issues with fence posts in that corner of the garden, ground stays quite damp, so want to make sure to keep the frame away from the rot as best as possible.
Yep, I would go hardwood or composite if you are planning on keeping it any length of time.
In terms of the frame, are you concreting the posts into the ground? If so I would think about what wood you are using there, as standard 4x4 posts will rot out faster than anything else, you can slow that down a fair amount by using post savers or slow it even further by using a harder wood for the posts. I used 8x4 oak sleepers ripped in half, and then put post savers on as well for double protection.