LiquorLanchyou may want to wait, GPU prices are pretty high right now.
this, you could get a 1050 or maybe a 1060. but it might be better to get a used rx 480, 580 or a 1070 1080 or even a 980ti. 1060's and 1050's are ok, but your not gonna be maxing out gta 5 graphics on them for sure.
if i were to recommend for 800 bucks, 1050 ti, 1060 or 480 if you can find it for cheap somewhere, it should run you around 200 bucks.
an msiz270 gaming mobo sells for about 100.
power supply i would recommend something with customizable power cables, there less wonky and if something fails, it normally is the cord anyway, a decent one should run you 80 bucks.
i got a hybrid ssd/ hdd terabyte drive, i think i payed 80 bucks for mine.
for a cpu you can get a fine one for 200 bucks i got an intel i5. for 300 but anything with 3.4 ghz will do you just fine, just remember to make sure that your mobo has the proper chipset for amd or intel.
and ram is ram, i got 16 gbs of ram for like 90 bucks.
so that will run you under 850 i think which would leave you money for a nice gaming mouse/ razer keyboard.