I am house hunting right now. Most of the houses in Philadelphia
suburbs, that are in my price range, have no central air and in many
instances no ductwork. I am considering buying such house and
installing AC system, so I want to know ball park figure of hiring HVAC
person to do these jobs (parts/labor).
I tried to call a few local HVAC establishments. They offered to sent
somebody to the house to make an estimate. Problem is I don't have
house yet!

Here is the sample house that I am looking at right now:

70 year house with little/no insulation, single pane wood windows.
Radiator heat. 230V circuit exists.
Basement:
unfinished, no cooling/heating needed:
1st floor:
Living Room: 20ftx13ft
Dining Room: 12ftx12ft
Kitchen: 13ftx10ft
2nd floor:
room 1: 12ftx8ft
room 2: 13ftx11ft
room 3: 12ftx12ft

There are three solutions that I came across doing research on the web:
1) Install standard ductwork and vanilla central air system. I am not
sure if there is acceptable place to run the ductwork.
2) Install high-velocity system (space-pak?) with 2" ducts. I heard
this system is not as efficient as others.
3) Install two mini-split systems. My sample house has 6 rooms, but I
could not find any mini-split systems with more then 4 zones (install 2
systems - 2-zones and 3-zones?).