This RAW value means nothing to you disregard it.
Here is on understanding SMART attributes.
PLEASE completely ignore the RAW_VALUE number! Only Seagates report
the raw value, which yes, does appear to be the number of raw read
errors, but should be ignored, completely. All other drives have raw
read errors too, but do not report them, leaving this value as zero
only. To repeat, Seagates are not worse than other drives because they
appear to have raw read errors, rather they are the only one to report
the number. I suspect that others do not report the number to avoid a
lot of confusion, and questions for their tech support people. Seagate
leaves those of us who provide tech support the job of answering the
constant questions about this number. Hopefully now that you
understand this, you will never bother a kind IT person with questions
about the Raw_Read_Error_Rate RAW_VALUE again?
Regarding getting OS X on computer you can either clone your existing install (like mentioned before), start with Internet Recovery (pressing cmd + r) or prepare bootable USB key with installer with Diskmaker X utility or manually
System on SSD for sure be a lot faster than on HDD