Purpose of putting vanity over the pump - this is an option and not a requirement.
Guess this seems pretty obvious to me - sorry its not obvious to others. In my situation I just don't have 6 sq feet of space to dedicate to this - without removing the shower. I don't need the interior of the vanity for much - if I'm (and I say "me" in the royal sense since a licensed plumber is doing the work) careful on locating all piping, once the pump is installed and plumbed, a vanity with the bottom cutout and one side notched could drop on top of it, acting as a dual cover, sound insulator - while permitting a sink to occupy the same vertical space. If the whole thing is designed to come apart easily - well then there's the access to the pump.
I had such a vanity before you would disconnect the two water inlets and the drain, the whole top lifted off, then the cabinet lifted off.
Again, if that doesn't fly for some reason then I (royal "I") would construct a small box to cover the pump, and I then place a wall mounted sink over it. That is, box the pump and the sink drain.
Note that on page 4 of the Liberty Pumps Pro-370 shows the outlet rising about 6" then going horizontal:
http://www.libertypumps.com/Data/InstallationManual/7225000D_ForWeb.pdf
If the basin goes where I believe it could go, then the horizontal run is only 18". It may be possible to use 45 degree connections and not 90s with a cabinet acting as the enclosure. OBVIOUSLY this would be discussed with the licensed plumber doing the work.
I DO understand that if the cabinet/sink option flies, that the interior of the cabinet is going to be gutted and not provide any other useful function than holding the sink up.
David
PS: in a past life I had a house built. We had a basement bathroom. We had the ability to lay the drain pipe before the pour - so it ran about 20 feet to an unfinished part of the basement. No problem. Jack hammering a 25 foot run in an older house just doesn't seem like a good idea, but then, I am looking for a good solution so do not discount this out of hand.