You need to get a comprehensive water test. If you already have a complete test report, perhaps you can scan it and post it here so you can get help interpreting it from people who are probably too far away to worry about selling you a water treatment system.
Tell us if you have a shallow or deep well, and anything else you know about the well or system, and kind of pump you have.
Reverse Osmosis takes out dissolved solids (chlorides, sodium and calcium ions, sulfates, and others too numerous to mention). You should get a result for Total Dissolved Solids (TDS) and if it is more than 500 mg/liter you MAY want to consider RO.
A 24 Gallons per Day RO unit is one gallon per hour. That is hardly a good drip. It is probably a waste of money. If you want one anyway, check here:
And look at their whole site. http://www.waterfiltersonline.com/ (I am not their agent and don't use their filters.)
The initial turbidity was probably due to iron (rust) in the system, or junk that collected because the system wasn't used. If it doesn't return, then 0.3 NTU is good. Turbidity of 5.0 NTU is not good. It is usually less than 1.0 NTU in a decent well.
You will want to know the pH (6.0 to about 7.5 is good, 6.5 to 7.0 is better.). If it is too low you may need an acid neutralizer.
You should have a coliform test which will report if there are any fecal coliforms or E. coli in the well water. If they are present, you will need to chlorinate the well and get the test repeated. You may already have that result.
There should also be numbers for hardness, iron, manganese, and whatever else may be a problem in the area.
You probably will not get results for VOCs (Volatile Organic Compounds) unless you paid for an expensive test. They would be indicators of serious contamination and are usually only tested for if you are near an junkyard or industrial site, or if you smell or taste something like chemicals in the water.
There are too many possibilities to make more guesses or suggestions. If we see your water test results (the second series) you will probably get a lot of suggestions about whether and/or what treatment you need.