If you are wanting to build your own
Nooelec NESdr smart v5
(Just the dongle, the antenna & coaxial isn't worth it)
Build a 1/4 wave ground plane
Software
Dump1090(inside the source download it a file dump1090-win.1.10.3010.14.zip / extract and put folder in c drive)
Virtual radar Server
(When installing it gives you an option to change the port, default is 8080, I would change it to avoid conflicts later on)
A stand-alone .NET application that displays output from an SBS-1 ADS-B receiver on a Google Maps web page.
www.virtualradarserver.co.uk
Side note; the nooelec NESdr v5 or the RTL-SDR blog v3 are great if you guys later want to explore other rtl-sdr projects.
If ads-b is the only intrest , I personally like & use the
The all-new ADS-B FlightStick is RadarBox’s latest ADS-B receiver USB dongle. - AirNav RadarBox - Global Flight Tracking Intelligence | Live Flight Tracker and Airport Status
www.radarbox.com
With this I just use rg6 quad shield coaxial cable, and adapters f-type to sma and f-type to what ever connector use may use in your 1/4 wave gp build