Grace Infant Car Seats

I'm looking at the Graco SnugRide SnugLock 35 LX Infant Car Seat. There is one at Target that has "Safety Surround Technology" and one on Amazon that has "TrueShield Technology". What is the difference? Also looking at the Graco SnugRide SnugLock 35 Platinum Infant Car Seat.

I'm expecting twins in Feb. We drive a 2015 Acadia (2nd row has captain seats) and a 2008 Equinox. We would have bases in both those vehicles. The twins would also be riding in my fiancé's mom's vehicle which is a Flex but would not have bases. In our vehicles there would be no one else riding in the back most of the time.

The other car seat we are looking at is the Keyfit but we saw this one at Target today and liked it. Thank you!