I just wanted to reiterate this excellent advice. Lightweight backpacking is much more about leaving stuff at home than it is about buying fancy stuff. And trust me, for that hike, you will want to have as little on your back as possible. Pair down your clothes to the absolute minimum for the worst weather you could face. If you hit unexpected cold weather and aren't a bit chilled with everything scrap of clothes you brought with you on your body while in your sleeping bag, then you brought too much.

I haven't been to Havasupai (it's on my list!) but you should find out how the insects are during the when you will visit. If there isn't much chance of insects, a tarp would be better in the heat, lighter, and cheaper compared to a tent.

Also, you are new here. We are trying to feel you out as much as you are trying to feel us out. You shouldn't be so quick to be offended when asking for free advice on the internet. It is worth every penny you spent.