with an i7 is should last you a few years. i would make sure all your hard drives are 7200 rpm and you buy a name brand ssd drive. it the parts and firmware on a ssd that make or break a build over time. the cheap ssd will just brick themselfves over time. even intel has issues with some of there ssd (330 line having bricking issues).
Your highest priority is gaming. There's no way to know exactly how hard future games THAT YOU MIGHT USE will tax your system. Historically, games push computers more than any other commercial software so there's no doubt it will be useful for other things long after it can no longer game. The best you can do is to build the most powerful computer yo can afford and I think you've done that unless you want to try water cooling.