Transponder

We pretty much had to go with the Bendix/King unit.

It wasn't what we wanted but Garmin wouldn't sell us a Garmin transponder unless it was installed by one of their dealers.

Why?  I have no idea, perhaps to make sure everyone gets some of the pie or perhaps there's something they left out of the brochure, all the techs at Garmin would say was that it was their policy and if we wanted it that it would have to be their way, lol, go figure. 

The Bendix/King unit looks like something you'd buy your kid at K-Mart and we weren't at all impressed with it.

It is built cheaply, has a very poor mounting rack and even the plastic face is cheap looking and it fits into the rack with slop that's made up for by a big nail in the rear of the rack.  Perhaps we just think it should be different because of the price, who knows.  The unit we bought came in as an upgraded unit and didn't look like the one we ordered did, which come to find out was old world stuff and the unit we got was supposed to be new and up to date.  Bendix/King also has a builders kit so be sure to order it when you get yours and you will get all the goodies you'll need to install it.

One good thing is the folks at Bendix/King know their stuff and they have good techs who have an answer for everything without having to go ask mama for it as long as you have time to sit on hold long enough to get through to tech support, but once ya got em it's time well spent.  From what I got from this experience avionics resellers buy units in volume and send you things in pieces so they can buy out from different sources and perhaps make some extra bucks on the sale.

Depending on who you order from you can get nailed real quick

because some things come from Bendix/King in the box and some places charge you for it on a piece by piece basis, even though they get it all in the same box and are supposed to sell it that way.  A good example of this is the wiring harness and the antenna, if you buy it from Aircraft Spruce it comes with it at no extra charge but if you buy it from your local avionics store at the airport it doesn't, they hit you up for an extra 90 to 150 bucks to make the harness for you plus sell you the antenna, adding up bucks to an already expensive purchase.

All in all we shopped eight places for all of our avionics and got a variety of prices and in the end we got it all for about $3,500.00 less than we would have paid have we just walked in someone's door and said Gimmie!  One thing that will make it easier for you to get quotes is to compare apples to apples because a lot of venders have their favorites they sell and don't necessarily want to sell you what you ask for but they will if your specific on what you want.