I recommend this GPS receiver. It works perfectly with the PiGate. To make your life easier, GET A GPS! It's less than $30!
Custom Cases Brent Parker, W8XG, can make a custom case, like the pictures shown of a case that he made for me. Contact him at firstname.lastname@example.org or see his website at www.PiGateCase.com
If you will be using HF radio to connect to a WinLink2000 RMS station, you must have a USB to serial dongle and a cable to your PACTOR modem. I recommend this dongle: https://www.tripplite.com/keyspan-high-speed-usb-to-serial-adapter~USA19HS These dongles can also be bought from eBay for a lesser price.
To make your project easier, I recommend using this application to copy the PiGate software image to your SD card, https://sourceforge.net/projects/win32diskimager
NOTE: When assembling the PiGate, put several layers of electric tape on the top of the Raspberry Pi USB connectors to insulate the metal housing from the pins on the bottom of the TNC-Pi board.
Here are the pieces you’ll need to build a PiGate.
Assembly is as simple as plugging the TNC-Pi into the Raspberry Pi, inserting the mini-SD card with the loaded software, and plugging the custom data cable into your VHF radio. This is an easy plug-and-play device!