Upgrading some stuff

Hello, I had bought a pre-built computer about 2 years ago and a year ago I bought some new parts. The old one had the GTX 760 and I upgraded to the 970, the CPU was i5-4440 and now I've upgraded it to i7-4790k. The most thing that bothers me is the motherboard, I mean, it feels like it's not as functional enough as it should be, it's the MSI B85M-E45, it feels like it's not future proof, what motherboard would you recommend if I ever wanted to SLI 970's(I've been thinking of doing that) and what PSU is fairly good for a SLI config. I've got the EVGA NEX650G And is it worth upgrading to a DDR4 motherboard? If so, any good ram sticks? Would appreciate if you could drop Amazon links since I'm a refunder myself haha, can get the things for free.

My current setup looks like this:

Motherboard: MSI B85M-E45
CPU: i7-4790k
RAM: 2x4GB RAM STICKS(too lazy to open it up to see what brand it is, but I assume it's not bad)
GPU: GTX 970 4GB
Cooling: Corsair H100i
Case: Corsair 750D(dunno the reason I actually bought it, it's damn huge, it was like 180quid, bought it from Amazon and SE'd it anyways so)

check on tomshardware there are more computer savy members on that forum and they will help you out

nice build