If you want to invest a little extra in building out your ultimate backyard course, consider swapping out some of your homemade PVC pipe and lacrosse ball grips for some authentic hanging obstacles just like the ones on Ninja Warrior. These Atomik climbing holds are the best we've found. Here's a tip: if you get a set of each type of grip, you can use carbines to clip them in, so it's super-easy to swap them out for training on different days of the week. Very cool.
If you are looking to complete your course with the cargo net and Tarzan ropes then check out http://www.ironcompany.com/outdoor-climbing-cargo-net. They have some really quality climbing nets and they ship for free!
If you want to take your training to the next level, then check out these other extras to really round out your set-up. For our personal course we've added a slackline for balance training as well as padding under the salmon ladder (just in case). We also sometimes throw on the forty pound training vest as an extra challenge. It takes a while to get to that point though, so you may want to try a ten pounder or twenty pounder first. The rings are great to train with as an option on the peg board side of your set-up, or you can just clip them in and do hanging core and gymnastics work. The rock rings are great for finger strength ...and, well, the chalk ball is self explanatory (you'll want to stock-up on a couple of those ; - )