You could probably budget for a GTX 970 since the 1060/1070/1080 have come into play they are going cheap now.
http://www.ebay.co.uk/itm/121941251301? ... rmvSB=trueOnly problem going with the older gfx card is even 4GB memory isn't going to future proof your pc against more demanding titles that release in the coming years. GTA V can take up that 4GB usage on max advanced settings. On my latest stream test I did my game settings on GTA were showing 4059MB vram usage and that isn't counting the stream. If you prefer older games then sure it will play fine.
I'd go for i7 especially if you want to stream in good quality. 8GB ram is fine imo but if you can afford another 8GB later on then go for 16GB.
I use the evo 212 cooler and it gives great temps. Idle around 28-30*c and rarely see it go above 70*c. I used to have all-in-one watercooling but it sucks imo.