pumps - surface vs submersible

System

Hi again from Spain.
I have a 10metre deep, 1.5m diameter well, presently with the water level at about 5m below ground level. I have inherited a surface pump with the well (sorry, don't have the details with me right now, will report back later!). It presently works off a genny (well, it's not actually sucking yet, but we hope to get that rectified).
I want to convert the water pumping sytem to solar. The well is about 30m from the house and the roof mounted water tank is approx 6m above ground level. I am not averse to replacing the pump if advantageous. I have also inherited two 50W BP solar panels that were running a basic lighting system but are now being replaced. Will these be adequate to operate the/a pump?
Any suggestions please as to operating system, suitable/better pump types? Is surface preferable to submersible or vice/versa? :?