If I had to buy a new kit today for a $1500 budget, and I expected to use it again somewhat regularly, it would look something like this....
Knife, rope, and compass are 3 items commonly on packing lists, but they can be passed if a) you don't know how to use them properly, b) your trail mates have them covered
You said your friends will have a stove so I left that out. Otherwise a MSR MicroRocket + SnowPeak Cup make a great combo. You could always make a cat can/penny alcohol stove which is light and cheap.
Your extra clothes stuffed inside a bag works well as a pillow.
Smart water or gatorade bottles are great additions or replacement for the bladder. They are cheap/free, plenty durable, and some people prefer them for hydration.
Clothes are a whole other ballgame. For summer trips in VA - you should be okay with 'gym clothes' the majority of the time. Probably a rain jacket. At night you may need a pair of leggings or fleece/down jacket. I like to sleep in a buff/beanie too. You don't need an extra change for each day. 1 change, plus a pair of clothes to sleep in should be fine. Maybe 3 pairs of socks (wool) and undies. Baseball cap or bandanna. Maybe sunglasses, although the trail is pretty covered in that area.
Trail runners work well for most sections of the AT. Depending on what condition your feet/legs are in. They are more durable than tennis shoes, but less rigid than heavy leather 'hiking boots'. Mid-top boots work well too. I like a pair of flip flops or crocks for camp and river crossings.
Food is another subject this gear post doesn't cover. A whole world of options there...
I spent most of the money on the 'big 4' at the top. They typically weigh the most and are the most paramount to comfort. Spending big here really makes life better. A lot of the list below these items is optional or super personal preference. Not including shoes or clothes in the budget is risky, because for some trips you can spend more on these than the rest of the kit. I'm just assuming that on a 3-season trip in VA you won't need much technical clothing (except for wicking sweat).
hahah "what say you"...you remind me of when I was raised in Alabama.
To borrow your other expression, killing two birds with one stone, I purchased the Sawyer Mini and the squeeze system came with it free. I havent used the squeeze system, as I usually just attach my Sawyer filter to a water bottle as opposed to a bag. Here's a link to the one I purchased: http://www.amazon.com/gp/product/B00MPH1LEU/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1
If you can afford the titanium cup, definitely go for it. Since most of us are trainhoppers and hitchhikers, I usually try and suggest the lowest cost items. But hey, if you just got a chunk of change from farming, hats off to ya, and definitely try to get better quality stuff when you got the dough to blow!
As for pepper spray, I dunno, I've vagabonded around California, Oregon, Washington, and Alaska. I had one encounter with a bear, and luckily it was in the peak of salmon season, the bear was so fat it was about to explode, and it just laid down on the rocks and stared at me and my friend while we were fishing. Perhaps I was lucky.
If you are concerned about bears, go with your gut. If you don't think it's too much to pack, definitely get it.
(Sidenote: I've always been told that bear spray is stronger than pepper spray. After reading about it, the opposite is true! Pepper spray designed for humans is nearly 10x more potent and concentrated! Knowing this, I think you are better off with regular pepper spray, for both bears and humans.)
I don't understand why y'all keep going for Lifestraws. Do you intend to have a cup with you, or to lay on the ground to have a drink? A Sawyer setup is more portable since you can fill a pouch with water and keep going. Bonus: it costs the same or a fistful of dollars more than a Lifestraw.