DX Geothermal Pond 4 ton Heat Pump

[MEMPHIS91]

Greetings and welcome to my largest project yet, and by far the most expensive. I currently have a old 10 seer 4 ton air source heat pump that is on its last leg. I had plans to replace with a new unit but considering the cost and how doable this build looks I plan to build a DX (thats right no water pumps) geothermal heat pump (R290 of course) that uses a 3 acre, 17 feet deep pond/lake that is 40 feet from the edge of my house.
I currently have NO parts for this build. Of course I will be buying the copper tubing and I have all my sources out looking for a suitable compressor.
I really don't know where to start with all the data so might as well give a diagram of the house and 3 options I have thought up.

This is the distance that everything thing is apart. The pond at its deepest is 17 feet deep, and I get average temps in the 60's.


This is just a few ideas I had. No numbers are solid just guesses based on just a little math.

1 is 2 long loops buried deep (I have free access to a back hoe, so as deep as I need to go) that come out into the pond about 6 inches from the bottom.

2 is taking 2 larger lines out to the edge of the pond and brazing in a manifold that splits into 3 (or more/less) loops.

3 is long lines from the house to the compressor/s at the pond with a manifold/or long loops.

I'm really open to any and all suggestions.

I am thinking that about 800' of 5/8 copper tubing would be about right. So the smaller runs will be longer.

Also should I have 2 compressors, one 4 ton sized, and one 2.5 ton sized and hooked up with reversing valves so I can only use the 2.5 ton on mid days and for dehumidifying.

Thanks in advanced for all warnings/ideas/designs/complaints/or general help.