I will go the middle ground here. Since you have not stated what resolution or frame rate you are targeting, I will assume you need a gaming card now, but would like to maximize your bang for the buck. I would recommend you pick up a 1050 ti at the best price you can find, and hold the rest in...
I typically do a full system build every couple of years, with gpu upgrades as needed. Every time I do a full build I switch cases, and rarely reuse existing fans. The only exception to this would be my most recent build, when I migrated over a trio of Thermaltake RIING rgb fans that were less...