Do you mean i7-3770? Just curious, because the 4770 is LGA1150 and a Z77 mobo is going to support LGA1155.
For caching, it doesn't matter, both generations support it. It is a software/firmware based set up and you have to install Intel Smart Response Technology (or Rapid Storage Technology, as it is now). The limit is 64GB, so to use a 128GB SSD, you would partition off 64GB (or less) and pair it to the HDD and then use the other half for whatever you want. The 'accelerated' disk is listed as one volume in Windows and you can accelerate a boot drive, you just have to install Windows first.
As for reliability, there are a couple settings that make a big difference. You can get better performance if you only write-back to the HDD at intervals, but you risk data loss. Not usually good on a boot disk, and I have heard of this ruining a Windows install. I personally don't do it.
For a drive of the size you have, 128GB, I would just use it independently and install the OS directly to it. You have a great SSD, but make sure to install it on a SATA 6Gb/s port or it will be bottlenecked. You have two of these ports and I would just connect both disks to these for the time being, not that it should technically matter.
If you want some stupid crazy speed (and don't mind reinstalling Windows every two months), you can get another 128GB SSD, preferably another 840 Pro, and put them in RAID 0. That is what I use for a boot drive (well, I have regular 840s) and it's fast. Like 957MB/s sequential reads fast. Is it worth it? No, probably not, but it is fun.
Other options would be to partition off something like 32GB of the SSD for a cache and then install Windows on what's left. There are a lot of things you can do. Just ask if you have questions.