Ok I am new here but will chime in anyway
Because of my engineering background I tend to build a great deal of my Turning kit up to and including lathes.
Toolrests I tend to make them due to the cost of buying, sometimes they are over the top IMHO.
I currently have a couple made out of hardened 25mm round bar for my old Woodfast 400. The pin is 3/4" and is welded to the toolrest bar. To do this I had to heat up a small portion of the rest just prior to welding and use arc welding rod suitable for welding dis-similar metals
Being far away or close is a matter of what your turning. I turn mainly bowls, Vases, and Hollow vessels and not all my toolrest will go inside to give max support. So the distance between the job and my toolrest really does not come into it.
I have in the past used square bar on my big lathe 25mm sq with this one I can get inside easily and here the toolrest is kept close to the work.
I have in the past made smaller ones from angle iron 30x30x8 and 25x25x6 for a friend doing pens.
To some extent its horses for courses and personal requirements or preferences.