Beginning questions.

[WineYooper]

First, thank you to Grapeman for the beginning to end thread going. I'm looking forward to more and loving what I'm seeing. I have a small planting going in comparison, 18 vines, 6 Marquettes, 6 St Croix, 6 Catawbas. *** 24 but messed up on ordering and the Frontenacs were sold out already. Ordered dry rooted from Double A and planted May 26. On June 9 they were just starting to bud out and the 16th were leafing. I can always expand if the others do well, have a 10' x 10' spacing set up north/south direction and could expand to 15 rows with 6 in each row. If these look good I have another spot with great dirt about football field size. The gamble is the climate 12 miles south of Lake Superior. Looking at being near these in the future but will do the best I can from 200 miles away. Have set up someone to water if it's dry so I'm covered there. Long in getting to the question, is the wire, 12.5 ga., solid or stranded that is typically used? Also, would I be fine with two end posts and one intermediate post? In the search mode and looking at some pictures it looks like I'm seeing four vines between posts. How about the new tubes Double A has with the side opening, is this the way to go?