The method I use is my chain link fence ;-) I just train the vine up to the top and then have it go outward along the top of the fence and another set going outward about halfway up the fence.

A pretty easy solution that I haven't tried, but it seems like it should work, would be to go to a farm supply store and look at their fence panels for livestock and such. I forget the name of the fence type, but it's very strong and has just 2 or 3 horizontal poles between the vertical posts. No assembly required as they come in one piece. You just dig holes to anchor them and instant grape trellis.

I don't think the east-west or north-south orientation really matters as long as the area is full sun. Also, when you say one of the areas is wet, how wet? My grapes are growing along my property line where the water run off goes so it is actually swampy in the spring and the grapes, to my delight, don't seem to mind at all.

I don't think I would recomend choosing a wet area, just saying it doesn't seem to be an issue. Your mileage may vary, of course.

I put in 3 - 4x4 posts and stretched aluminum wire at two levels between them. Total length is about 25 feet. I put aluminum turnbuckles on the wire.

That was 12 years ago. I planted four vines. Just two made it past infancy.

I brutally prune them every year, creating a huge mound of cutoffs. I find these useful in the garden -- my pole beans grow up vine cutoffs.

The vine growth is so vigorous that it could be dangerous for a small child if he stood still for too long by the vines :)

Yield is about three to five 5 gallon buckets of grapes -- we have cut way back on canning, jelly making, etc so some years they go to rot. In fact, the principal consumption in the past few years is me as I whiz past on the lawn mower and reach out and grab a handful.

If the weather is right they turn into great raisins on the vine, but mine have seeds.

There are two varieties. One is Fredonia, but I have forgotten the name of the other -- a bit more reddish. If I planted them again I would add a seedless variety.

Aside from pruning every year and tightening the turnbuckles every couple of years, they have been a zero care item. I have never dared fertilize them for fear they would get more vigorous:)