Well you really Don't have to have a 30 foot hose.  Provided there is enough outlets for the suction tubing. 

Friend put a central vac in his house (built in 1960's) he put in enough wall 'outlets' so it's only 20 feet between outlets. The hose he's got isn't nearly 30 feet long, doesn't need to be.

Of course,, the advantage is by putting the system yourself,, a person can do the job 'right' instead of paying someone to get it done "easy as possible"...

Would highly suggest getting the 'powered' outlets so the rug attachment can run a motor, (powered) rug vac.

There's no subsitute for power,, 5 hp motor at the main Vac canister is better.
As Tim Taylor would say "more power".

Edit:  Forgot to add, make sure and get the "dust pan" accessory I believe it's called,,, It's a door that sits at floor level (generally put in the kitchen but could be put under cabinets anywhere a person will be sweeping the floors)  sweep the floor, hit the switch to open the "door" and the vac turns on, simply sweep the pile of dirt/dust etc.. into the open suction, close door vac shuts off.   Great deal for sweeping up  dirt, or the occasional messes!!