Best GPU for MSI H97 PC MATE

So here my 4 or more yeasr old PC (bought from old good E-KEY, RIP) That I already upgraded with an SSD and extra 8 gb of ram and it works fine. But now I bought a new samsung monitor with FREESYNC and I want to upgrade the GPU too (just the GPU).
So the question is: what is the lastest and best compatible (AMD for freesync) GPU for my motherboard?
I use it mostly for gaming and some graphic design (adobe) thanks in advance !

1 x Alimentatore PC Thermaltake Berlin 630W 80+ ATX € 45,20
1 x RAM DDR3 Crucial Ballistix Sport XT 8GB (4GBx2) 1600MHz CL9 € 64,40
1 x VGA Sapphire AMD Dual-X R9 280 Core 850MHz/940MHz Memory GDDR5 5000MHz 3GB DVI HDMI DP € 178,80
1 x CPU Intel i5-4590 Socket 1150 3,3GHz 6MB 22nm HD Graphics 4600 Boxed € 171,30
1 x Scheda Madre MSI H97 PC MATE Socket 1150 Intel H97 DDR3 SATA3 USB3 ATX € 70,10