I store mine hanging by the tips from something I fashioned from an old counter and is installed above an upper cabinet. I cut narrow slots in it (maybe 1.5" wide) and hang the skis vertically; similar to the dowel method.
The ski school I work at uses pegs in the wall about 5 feet up and several inches apart. They aren't there to hang the skis from but to keep them from sliding left or right. I think this is something you should consider since you'll have so many skis in there. It will become annoying if something is bumped and the all fall like dominoes.
Indoor/outdoor carpet or a mat on the floor would be good to catch any moisture.
You might want to segragate it length wise and not height wise; skis in this section, boots and helmet behind another door. Should you want to go with a built in boor dryer, you should be able to easily fashion something out of pvc that will handle all of your boots. Maybe make it a summer project for the kids to keep them busy.
The following isn't really a hijack as it should be considered in ski storage, but is a little bit of a rant.
With regards to camber and the concern of it mysteriously disappearing during storage, consider this:
When skiing, in full ski gear, the average adult skier is easily over 150#. The average on snow ski day is about 6 hours and lets assume 1/3 of that is on the lift with the skis hanging (I'm counting waiting in the lift line as on snow time), and we'll round that down to 3.5 hours of your skis bearing your weight plus the g forces of skiing.
I think everyone would agree that if they put their skis base to base, they can press the bases together in the center (no camber) with their thumb and index finger. It isn't hard at all and takes almost no effort; maybe 25# of force?
Should you be able to carve, you are going to press your skis PAST flat and they will come back to full camber. If you go in the moguls, you will probably do the same. Same with crud.
So, our skis survive our skiing which bends them to extreme measures under considerable force for hours at a time, but they can't handle the pressure that a young child can exert with their hands. Granted, the forces of skiing aren't constant and the minimal force of storage is, but someone is going to have to explain the math on how that works and how long it takes to happen. How do they survive a season of 50+ days seeing 180# skier exerting 2 to 3 G's (will feel like 360 -540#) while skiing but not the weight of the ski and binding (roughly 10#) for a couple months.
I also think most of us will replace our skis or break them way, way before the decamber from use let alone storage.
Without a doubt, a racer or other hard skier, will suck the life (camber) out of there ski in a season or two, but that is from how they ski and the frequency of it and not from storage. The skis will be bent and bear incredible forces for longer periods of time on average. I am also a little skeptical as to how fast this actually happens and how much of it is racer 'bravado' - "The way I ski they don't last more than a season!" Really?
Has anyone ever bought a pair of brand new skis that were more than a year old that were stored in any special fashion? If the bindings aren't on they are on top of each other to save space but if the bindings are on, they are base to base.
I'll be the first to admit I'm wrong as soon as someone can prove it. Anecdotal evidence doesn't count.