I can't remember the 17" being offered in core i5 configuration. Was it? Seems like there were only two proc choices each release. The latest, 2011-- early in the year the 2.2/2.3 and in October/November the 2.4/2.5 options. The higher clocks also had a larger cache if I remember right.
IOW...you don't have to worry about the i5

We have a pair of 2011s. The 2.3 and 2.4. Both with Samsung SSDs. The 830 and 840pro. Both with 16GB of RAM. We stripped the OD from one and put the 750GB stock drive in its place. The other we've kept the OD for different reasons, namely burning discs for clients on site that still prefer a 'physical' copy...not on a thumb drive. You can get some excellent deals on those models. $1300-1600. Just be careful and If possible see if you can still buy refurb from Apple. Those are essentially new machines for nearly a thousand dollar discount.
J