Fast and reliable GPS modules

I am currently working on a GPS controled rover and I am having trouble to get reliable GPS data to drive the robot back to a desired position.
The GPS module I am using is a VK16HX, I can get GPS data but it does not seam to be reliable and it is not updating fast.
I am using an arduino Nano, a LCD module, motors etc … The idea is to memorize a GPS position and ask the rover to go back to that position. I have attached the code, so far everything is working fine appart from the GPS data
Any recommendations to choose a good GPS module (8.72 KB)

I am adding a picture of the robot

I don't think GPS works very well inside the house, or for very precise position localization.