Isaac, what area are you thinking for? Often makes a difference as far as gear.
– Pack –
Mine is homemade with super cushy Osprey harness. 20 lb you should be able to use a frameless pack, not even a real hip belt. The Golite packs deserve your attention as well. I hate attaching stuff on the outside of a pack, so I always end up with extra volume compared to others. A 25 liter pack is not enough for me most of the time. Alot depends on how easy you can take it on the pack.
– Sleeping Bag –
The pitchpine looks great. 17 ounces.
– Water Filter –
I use the Katydyn Hiker. 11 – 11.5 oz. It's rather a luxury in weight compared to the new pills, Steripens and such. Affordable – $45 at omc – and the replacement filters are one of the cheapest ~33. I plug my platy hose right into it for hassle-free filling and one less hose. Great for a group of people, they should scale it down.
– Stove –
Sounds like you are set on the stove. For canister, I like the Brunton Optimus Crux. Besides folding, it supposedly blasts out up to 12K BTUs, more than my very nice vargo-ti:
# 2.2”x2.9”x1.3” stove folded
# 3.1 oz
# Fuel: Isobutane canisters
# Rating: Approximately 3515 watts / 12,000 btu
# Burn time: Up to 70 minutes at high output
– Tent –
Howabout a bivy? Integral Designs South Col Event: 22 oz. I can't spend money on this right now so not really thinking about it.. There is a new crop of UL tent supposed to come out next cycle. Most of the summer just a bit of bug net is all you want around these parts. Decisions on tent and water filter can be affected so much by if solo or group camping.
– Fall and Winter gear –
Down jacket is nice, if you can keep it dry. Usually used between getting off trail and into the bag, unless extra cold. I got a Montbell Ex Light Down Jacket this year. 6 oz. It'll do me 90% of my trips, it's like a sweater, so I bring a 3oz. Golite Ether windshirt to back it up. For winter, I'd want more. Maybe take a hooded synthetic parka if expecting weather or not sure. Primaloft is the most packable supposedly.
Event rain gear is nice and breathable. I love hard shells so much, I might never catch on to soft shells.
People are loving the Icebreaker hoodies. Wool base layers in general. Patagoonia R1 fleece Hoody can cover a good temperature range, has more face coverage.
A stretch microfleece balaclava is very versatile. I sleep with it over my face on cold nights, rather than breathe into the bag. It can be used as a neck gaiter, a hat, an earmuff-headband, la la. Also a fun sewing project.
Good gloves and/or mitts can be key. I got some OR Verglas, Goretex paclite mitts off of Sierra Trading Post. They condense on the inside of the rubber palm a tad, but awesome when you have to go get snow off the tent in the middle of the night. OR Gripper gloves look like they would make good liners. If you ever want spare socks, winter will be the time.
In the tent, a small piece of sponge can help to help manage melt and condensation. A pee bottle can be convenient. For groups, maybe include a small brush for getting the snow off pants before entering. It's good if your ground sheet can be under the vestibule area as well, as a welcome mat.
Consider the ridgerest 3/4 foam pad in addition if on snow. I put it between the groundsheet and the bivy floor to lessen condensation inside.. Maybe full length would be better, never thought of that.
Goggles is a consideration for snowy conditions, both for sun and storm.