Disclosure: I don't own one myself as I use a tarp anchored to the bed of my truck (something you said you don't have). With that said, I've been pretty impressed with my camp buddy's Coleman canopy. Understand, however, that you need to anchor it well.
I think your camping supplies are fairly priced. I was never into climbing or hiking but camping has always been fun for us. One of the best things we bought for extra shade and shelter is this. http://www.amazon.com/13-x-Instant-Canopy/dp/B0033990N8/ref=sr_1_5?s=outdoor-recreation&ie=UTF8&qid=1425098158&sr=1-5 The sides and screens are sold separately.
EZ-UP are certainly the most popular but I have one of these I got after reading reviews on amazon: https://www.amazon.com/gp/product/B0033990N8/ref=oh_aui_detailpage_o01_s03?ie=UTF8&psc=1
and get some of these to help keep it down: https://www.amazon.com/gp/product/B000YPQPSW/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1