Go for the I3 8100 or ryzen 2600, For the I3 8100 you can pick anything up aslong it is 1151 v2 motherboard and for ryzen a AM4 motherboard. For around 100 the Samsung Evo 860 512Gb will do great. I do recommend playing at 1440p if you are going to buy that card with this kind of CPU to reduce bottleneck.
What RAM are you using with your current MB as if DDR3 this limits your options or you will need to pay for DDR4 Ram aswell ?
EDIT: Just saw your Sig MB and checked, you have DDR3 RAM which will either need upgrading (which i recommend) or you are very limited in your options on a new Motherboard.
And both the 2600 and 2600x are overclockable (in response to comments by stevenjemint)
Ryzen 5 2600 3.4 GHz 6 core
PRIME B350-PLUS ATX AM4 Motherboard
Samsung evo 860 500GB
500W psu (typo above)
GTX 750ti currently but will upgrade to 1080
Would i be able to oc the 2600 chip and would this build bottleneck the 1080s potential at all? Would oc too.
Ryzen 5 2600 3.4 GHz 6 core
PRIME B350-PLUS ATX AM4 Motherboard
Samsung evo 860 500GB
500W psu (typo above)
GTX 750ti currently but will upgrade to 1080
Would i be able to oc the 2600 chip and would this build bottleneck the 1080s potential at all? Would oc too.
Depends on the game AAA games will not be a bottleneck and in games like CSGO the OC will likely not help at all.