GPS requires adding an additional board to the expansion header of a Lollipop.
The LTE modem requires setting Debian to use the 'testing' tree for some packages.
BOTH are highly technical. Especially if you've not done this sort of thing in the past. We also do NOT support or recommend these yet. We're still fine-tuning and testing and more. In due course these will be better supported but for now they are for our advanced users.