speed GPS

Hello,

I would like to make a GPS logger. I would like to mesure the speed of a vehicle. I would like to use a 10 Hz GPS.

Which of the 2 GPS on the webshop are the most accurate:

the Venus 634 FLPX (with an external antenna) or a 65 channel SUP500F?

Kind regards,

Pedro

Can anybody give me some advice? Which GPS has been used, and had it a good accuracy?

Kind regards,

Pedro