External Serial Interface to Arduino UNO with Datalogger Shield

Which pin out should i use if i have a External Serial Interface to be logged with a Datalogger Shield ?

Your choice!. Use "softwareserial(rxpin,txpin)" . (to allow serial to PC/USB as u go)

What about the Coding ? If my Data Logger is going to log a long string like below:

$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47

Can the Serial.Read() handle ?

Any advice on the coding ?