David-
Regarding the draft collars: The Helium doesn't really have one–it's a "passive" collar that looks like no more than a hood ruff. The only face-area drawcord related to the Helium is the hood. The Phantom uses a horseshoe-style draft collar with corresponding back tube; there's no drawcord to cinch up but it works pretty well passively. The velcro related to that collar just helps join the upper and lower parts of the collar. The Western bags have a small velcro tab to join upper and lower, but they also use a drawcord for the draft collar itself–in addition to the drawcord on the hood.
Regarding down quantity: the Phantom 15 does use 20 ounces of down. So does the Versalite. The Helium uses 19.5 ounces. All the same amount of down. As far as real-world, non-data observation, I can only base that on what I see and feel on a daily basis. That observation is that, regardless of how much fill should be in each bag, the Phantoms do not loft as well as the other two bags you're considering.
Girth: The Versalite is a 62" girth. So is the Helium. The Phantom 15 is a 60" girth.
The "Super" designation was dropped this year. In the past it was used to designate bags with the draft collar system that is now standard on all their 20* and lower mummy bags.
I weighed the Helium and Versalite in store just now. I used the same silnylon stuff sack for both, weight of 0.7 oz. Helium is 2# 1oz, Versalite is 2# 2oz (both including stuff sack weight). For the ounce difference you gain the draft collar and full-length zip. Weights included hang tags on both. I sold the last Phantom 15 a while back and we haven't re-ordered one yet.
I wouldn't be concerned w/included stuff sack weights. Weights given for bags are bag weight. Also, you want to minimize the number of stuff sacks you carry. As a previous poster said (sorry, forgot name) use bigger sacks and get more stuff in them. Shouldn't need more than four.
Re: Alpinlite–I'd be surprised if it wasn't too big for you. Add 5 ounces (compared to Ultralite) and lose heating efficiency.
Lastly, as for actual weights, my WM Summerlite has a reported weight of 19 ounces–and that's what it weighs. My WM MityLite has a reported weight of 1# 10oz, and that's what it weighs, and my WM Antelope DL/WS is supposed to be 2# 13 ounces and is. Within ~1oz The Ultralite will be 1# 10oz, Alpinlite 1# 15oz, and Versalite 2#.