You will not only need the LTE version for the GPS you'll need the monthly data access to generate maps. Or you can pay 100 bucks for one of the Navi system software that stores you maps on your iPad.
There are many of the latter. I have CoPilot Live and it works well. No need for data connectivity as you drive-- that's great for overseas travel (where roaming is expensive) and travel out in the boonies.
As folks have said, you need the GPS chip which means you need the "cell phone" version of any iOS device.
It's a pity that GPS has been linked to the cell functionality since the first iPad. I know of no technical reason why that must be. A WiFi model should have real GPS too, IMHO.