find $1 -size +$2c ! -type d | xargs ls -l |awk '{print $5}'

find $1 -size +$2c ! -type d | xargs -t -I{} cp {} /temp

the above shell can list the size in bytes of all the eligible files in the specified directory. and then write a loop to count the total size.
The second command can be used to copy the files to /temp directory.