if you you're youngish and don't mind the weight for hte miles walked, you don't need to spend money on a down bag. Like others said, sleeping bag ratings are usually liars unless you see two ratings, comfort rating and standard rating. I usually backpack in places that hit 40 at night, and I just bring my non down bag. I don't mind the extra weight, i'm in pretty good shape. A person in good shape with heavy ass gear will outhike and okay shape person with light expensive gear
bring sweats, fleece sweater, 1 cheap 1 fleec balacalva and 1 fleece hoodie on amazon. wear those to sleep and you'll get through some pretty cold nights comfortably in your bag. Wearable insulation double serves as sleepabl insulation, it lets you hang around a bit longer at night before jumping in your tent.
i'll go for REI backpack instead of ozark, the backpack is too important and too hard to make properly at that price level. I took a guy with a no name "framed Pack" that the strap fell off 3 days in. Rei brand doesn't even seem that much more expensive. I'd cheap out on the rest. check my list where my typical equipment is cheap except for my backpack. https://docs.google.com/spreadsheets/d/1cag6zvaV2F8mAhU9PWqiizdceQdhZBcMo_K0Le5HCO8/edit?usp=sharing