Check out
LINKspecifically
http://www.geokiss.com/res-design/GSHPDesignRec2.pdf
for a good idea of what is needed... I watched my install pretty close (and still have a 63° house)
The guys that did my wells had lots of specialized equipment consisting of a drilling rig, backhoe, skid steer, tools to fuse the pipe together, a purger, grouting machinery, distributors and who knows what else... They had also done this once or twice before.
In my best guess if you went with horizontal loops rather than vertical as I did you could probably trench in your own pipe if you have access to or rent a backhoe and have the property to do so. But, I would guess, still need to hire someone to fuse your pipes, purge your system, pressure test, mix the methanol, add a fuse box, start the thing up etc...
Obviously if you are capable of some of these things you may be able to leverage that with the install company. For example I did all the fuse box/electrical work. I also had to move a considerable amount of plumbing and sewer line to make room for the larger duct that I needed. Accordingly the installer didn’t charge me for these things.
Whatever you decide, remember that geodean is right. When decision time comes are you confident that you won't end up with a 63° house during a 4 day holiday weekend?
Jordan