I agree with this 100%. IMO the NVMe solution is unlikely to benefit the OP and therefore a SATA-II solution is likely to be the appropriate one.
Now if the OP wants to tinker than the NVMe is a solution to consider. As long as the OP is aware that such a solution is unlikely to gain him much, if any, performance over the SATA-II solution.
I honestly have no issues tinkering. I've de-lided my own CPUs so a BootRom hack doesn't make me shy. In fact it makes things more fun. What is important though is that it is reliable.
Joke aside, you are saying that there isn't much of a performance difference between the NVMe solution and the SATA solution? I thought the difference was like day and night... And my understanding is that there isn't much of a price difference if I go for Intel's 660p NVMe.