I think your choice will depend on your vehicle. I have a spartan open-air early bronco. Due to AZ carry laws, I needed a way to secure my gun when entering a place which prohibits carry. After looking at many alternatives, I went with a titan gun lock for a few reasons:
a. the lockbox detaches from the mounting bracket for transport away from the vehicle.
b. no electronic components
c. it's sturdy
d. it presents your weapon to you
e. it's pretty compact
I think I paid $160 at a gunshow. Good luck.
http://www.titangunvault.com/