^ Yep, not everyone can afford (or needs to) spend a huge amount on their systems, so, please, give a figure you can afford.
In the meantime a few thoughts:
For a decent GPU upgrade the GTX1060 is a far stronger part than the current '760 and gives good performance at 1080 rez with plenty of eye candy enabled, but it's unlikely to push that 144Hz display in demanding titles without dropping said eye candy.
Aim higher and obviously it'll cost more, the GTX1070 would probably be the best cost/performance match for the current system and display-but only if you're aiming at the higher performance the little '1060 is still a decent card at 1080.
At the top of the tree is the now discounted GTX1080, and it's here you need to look very closely at prices, over here in the UK the '1070 and '1080 prices can overlap with top flight '1070s coming in at, or even over the price of some '1080s.
Adding the SSD would, in my opinion be the lesser upgrade, meaning if you have to spend your entire budget to secure the fastest card within reach then go that way, you can add a SSD as boot/main applications drive later.