Use this chart to find out the size you'll need. You have to anchor it in an overhead joist to support the weight, and your contractor may want to beef up the support.

Probably better to have a bolt with a nut on the other side, than a wood screw without a bolt.

Here is a link that might be useful: Stanley Eye Bolt Chart

I have a hammock chair on a stand. I put it on the porch in the summer, and in the family room in the winter.

Look in Amazon. I need a long stainless steel latch and I looked eveywhere. I couldn't find it and the stores said they don't make one. I went on Amazon found it in 5 minutes and a selection of them. I had it in 2 days through Amazon prime.