Are you using wood posts or metal posts? How much room do you have at the end of your rows?
You can do angled posts on the ends tied to earth anchors to hold them. But that would mean you need extra room at the end of the rows for the anchor wires. If you are tight on space, you might want to consider H-braces.
I use the earth anchors from orchard valley supply you can screw them in with a long handled screwdriver if ya don't have stonie ground. You have to order the brace wire separately they come in a pack of two with the Gripple. Type in earth anchor in the search bar, from the drop down menu you'll need the 40" Much easier then making an h-brace and you can always place a plant under it to save space. Hope this helps and goodluck to you and your vines. Oh yea they look like a big screw
Barbie