Installation of a water source heat pump

[budwiser]

Hello:
I am considering to install a water source heat pump'
my house is a single floor bungalow of 2300 sq. feet
with a non finished basement.
the well is 100 ft .from the house at 130 ft. deep 6" casing.
the pump is set at 125 ft. and is a flowteck 1/2 hp.
the water temp. coming into the house is 54deg.f.
When I had installed the well pump I let it run with A 100 FT. of supply line open for seven days straight and it never ran short of water.
The supply line is 1" pvc.
When installed I put in a return line to the well of 1/2 pvc.


Questions:

What size water source heat pump would I require for this size house,
Would it run off the plumbing and well I have now, or would a seperate new well be required
If possible what brand name would you suggest if possible.