This is a table I designed for a company in town, as you can see, it's made from I beam. I used clavos to give it a more industrial appeal, giving it the look of rivets. The oak wood planks give a great contrast against the natural rust finish. My favorite aspect of the entire design, is the drastic difference in the look of the chairs against the table.
When searching for iron railing designs, keep in mind that there are many, many different ways to fabricate the look your going for. Some applications call for a simplistic look, others call for much more intricate designs. A railing isn't the easiest of jobs, so keep in mind the cost, especially if your job calls for curved railings. I always recommend getting 3 quotes, start by asking any local builders that you admire. Builders usually know who's reputable or not.
If you're going for a more intricate design, ask them if they are going to use manufactured components. By using pre-manufactured components through someone like King Metals, it'll help keep the cost down. Remember, the more scroll work you use, the more expensive it will be.
For advise on railings, don't be afraid to give me a buzz. Your options are endless.