If the trailer you have now works fine just keep it. Gooseneck takes up a bunch of space in the bed and doesn't clear corners as well.

Deckover gooseneck is usually stronger than lowboy. Most deckovers are made for tandem duals even when they come with singles. You lose quite a bit of carrying capacity due to the unnecessary extra weight. I have done a lot of hauling a bobcat plus a couple thousand pounds of pipe and a pallet of concrete on a lowboy, never hurt it.

I have never had any problems related to triples. Triples make a smoother ride than tandem duals. I have heard that other people will take your triple axle trailer, load it down, spin it and bend the axles. I never spin any trailer loaded.