Two questions:

I have a large picture window in my 1880s row house and want to do a nice planter box of some sort. Its 69" wide, but of course the standard lengths are 60 and 72 inches. Should I go shorter or longer? at 72" I have to affix the box to the brickwork and at 60 it would be attached to the wood sill.

Also, in our area there are many homes with large cage-style wrought iron window coverings. These are larger than a planter box-- usually about a foot high-- and they project about 8 inches from the window. attaching to the inside of the frame. There is enough room to put pots in them. I wonder if there is a different name for these than "window box" or "planter box." They look a bit like a Juliet balcony. I have been trying to find something vintage/salvage but I don't think I am using the right term to describe these and just coming up with regular iron planter boxes. Anyone know what they are called?

Thanks!