Have had 2 fruit cages in our garden - lost the first one due to forgetting to remove the snow from the top, and not having put bigger netting up there for the winter in the first place! The side poles bent double and could not be straightened!! The second one is now several years old and is going strong. Some companies will make one that fits exactly the place you want them to go, we did this as our site is an odd shape (bit like its gardener actually!). Reasonably heavy black netting works well, squirrels did eventually chewed through one corner but have left the repair alone, don't know why but we are grateful.. We grow apples, red, black and white currants, blueberries, gooseberries and strawberries in there. There are supposed to be rapsberries too, but something went wrong there!!
Whether you make one yourself or buy one from a decent company, they are quite an expensive layout, so worth getting the best that you can. If full size a decent door is essential, the first one we had was very flimsy and allowed spaces enough to let birds in, which of course could not find their way out - not a good plan.