Well, I wouldn't say the upgrade is worth the cost, but here's a decent motherboard
https://www.amazon.com/dp/B014YN67E6 Yes, it's expensive, but it supports DDR4, ECC and all that jazz, and the reason why this Mobo is more expensive than others is because it has an Intel LAN (Which is FAR superior to Qualcomm Killer ones) and it's got a pretty decent sound processor built in, so if you don't want to buy a dedicated AMP and Dac and all that audiophile stuff, the built in sound components in this Mobo will do just fine. That and MSi is just a reliable brand, and it's got alot of options for expansions.
As for DDR4 memory, any non generic brand will do
https://www.amazon.com/2133MHz-Non-E...er+X+ddr4+16gb NOTE: THIS IS NOT ECC RAM
But in my opinion, I don't think it's worth upgrading anything in your system, Although if you don't already have an SSD, I'd suggest buying one, Samsung makes some pretty kick ass EVO drives
Upgrading to an i7 MIGHT get stuff done faster, but in rare circumstances, and a 980TI is still top of the line :) So I'd just buy an SSD (Or treat yourself to a nice 1440p IPS monitor)
Hope this helps, if you have any other questions, feel free to ask me about them