I would still suggest a wired connection. Is there a fence line that is close? Use fully armoured SWA Cat5e or Cat6 and run it along there or just below the surface.
You could go for a point to point wireless solution but total data rates will be well down on a wired Ethernet connection.
If you go for a local installer they will only be doing what you would - and you sound competent, so why pay someone else when you could the credit? There would still be the cost of running cable or installing a link.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
M H C
taurus excreta cerebrum vincit