Parker makes the hose material for Teleflex and they also make field assembled (also called reusable) hose end fittings. I'm not sure what fittings you have with the Garmin pilot but I'm pretty sure Garmin knows what they need to interface with Teleflex equipment.
Before Teleflex bought out Hynautic, Hynautic used to sell the feild assembled fittings. Teleflex recommends factory assembled hoses to limit their liability (and they probably make a tidy sum from the factory hoses too). I've installed numerous feild assembled fittings over the years and never had a problem with leaks.
Disclaimer: If you see emoticons, that means the above is written in jest. It is for entertainment purposes only. It is not meant to represent any actual persons, places, or things. It is the opinion of the poster that it is funny. Your opinion may vary. No animals were harmed in the typing of this post but a few egos may have been bruised.