I hope you don't have young children They would love to climb that horizontal rail.

Good point! I do have children but not super young. I will have furniture in front of it. Definitely something to consider. I like the horiztonal look over the vertical but yea safety first.

"Is this something i can order online and install myself?"

This is enthusiastic intermediate or advanced DIY work. Give yourself an honest assessment please.

Expect to pay several thousand dollars in labor, finishing excluded.

We found a custom iron worker to build our steel railing. Google ornamental iron gates, etc. It ended up being a little over 2k. Many folks wouldn't even come bid as the job was too small. We thought about diy, but in the end I am so glad we paid.