Well, the thing I disliked about that power pack shown in the document the OP showed was that it is "just" a 2-outlet power pack. I was raised on Speedotron power packs, which have (for the most part) 4 outlets or 6 outlets on each power pack; that means you can buy a power supply and have room to expand. The newer Profoto 2,400 watt-second packs that cost $2,200 and offer three outlets, with three flash heads at $900 each, are in my opinion, a good example of another system that is grossly overpriced for the beginner. Too many W/S through too few outlets for maximum flexibility.
As far as umbrellas in smaller shooting areas--conventional umbrellas, and most especially shoot-through umbrellas are a major PITA in smaller areas. Enclosed umbrellas like the Lastolite Umbrella Box and the Photek Softlighter,which are basically reflecting umbrellas with an outer diffusion cover, offer softbox-like light quality, and hardly any ambient spill in your shooting area. I think there's a big danger in looking at the "Strobist" type web sites talking about using shoot-through umbrellas with studio flash gear: when you start using "real" studio strobes with typical shoot-through umbrellas, the higher output and the wider spread of most monolights or studio heads means that shoot-through umbrellas blast half of the light forward, and the other half of the light backwards, so it spills all over the shooting area--and that can create its own fill light in smaller areas.
The enclosed, double-diffusion umbrellas like 1) the Lastolite Umbrella Box and 2) the Photek Softlighter are NOT the same thing as what Paul C. Buff and others call a "brolly box", which is just a shoot-through umbrella with a back cover on it...Annie Liebovitz loves the Photek Softlighter becasue it works a lot like a softbox, and is lightweight and easy to set up and maneuver,and it gives a beautiful quality of light. The inexpensive "brolly boxes" sold by others are, IMO, junky and are simply a terrible concept. Some of the inexpensive
eBay enclosed umbrellas that LOOK like the Photek or Lastolite have a lot of UV brighteners in their cheap-o fabrics,and are really not worth messing around with.
If I were in the market today to set up a studio, I would call Calumet and ask them to send me their catalogue,and I would do some real research into the various systems. The last time I checked, Calumet had widest selection of lighting gear of any single location.