does anyone have info on the best brand of ductless air conditioners?  Also does there need to be an air handler in every room of the house for whole house cooling or is there some other way to do it?

Mitsubishi, and yes you could go with a concealed airhandler and run several short duct runs to several different rooms.

I think you will find that a top end geothermal system will be slightly more efficient.

I think that efficiency, as always, will depend on the conditions. When a geothermal system operates, both the compressor and loop circulation have to run. Operation of a ductless mini can entail low speed operation for lower demand conditions.

In mild climates, it is worth determining if the lower upfront cost and more efficient operation of a ductless mini doesn't outweigh the benefits of ground source.

I have looked at geothermal systems and have ruled them out as too expensive - $60K here on Long Island. I have solar power on my house so the electric for the A/C is covered. Various geothernal quotations I have received from the local contractors all indicated I'd need about 3.5 ton of cooling for my home. I figure I'd have about 1.5 ton upstairs (smaller area) and 2 ton for the main floor. My plan was to accomplish this with a 1.5 ton ductless unit for the second floor and two 1.5 ton ductless for the main floor - all strategically placed.

I am a handy guy. But I have never charged an A/C unit before. I have access to the equipment if necessary. I understand that depending on the unit and the refirgerant line lengths, some charging of the system may be necessary. My question to those of you in the know would be is installing these units myself doable or would it just turn into a fiasco?

Not to take anything away from your capabilities but installing any a/c unit requires special tools, knowledge of how to use them correctly, knowledge of brazing copper, electrical controls, etc. Have been in the a/c business for 33 years now and still learning. Not to mention that you need to be certified by the EPA (section 608) and there is a huge fine if caught or reported to them.

How about going with appliances of LG. They are cheap as well as durable too.....