The cukes will do fine, they also like a BIG square tomato cage,
The melons will do ok with the netting,but the supports that hold the net should be stronger then wooden poles, I use the small 1/2 inch diameter electrical conduit pipes about 6ft in height with a 4 ft one on top, connect them with 2 elbow connectors and use about 18inches of rebar to support the bottoms(inside the pipes), it's cheap and works great!! I make them 4ft long just for the stability reasons...but I love them and when you can get a melon or pumpkin to actually 'hang' from the netting, it's really weird looking, but cool!!
They love being off the ground too!!! No more boards and 'earth bugs' to worry about...lol