the coolermaster PSU calculator actually lines up fairly well with OEM built machines (think acer and dell computers)
which basicly means that the number they state will run, but it wont be give much headroom for upgrading, or having the PSU run at a lower usage % (think heat production and lifetime here)
I'll count on upgrading my PSU if I upgrade anything major. Which isn't a huge problem as long as I have something functional while a save money for that upgrade.
If I add like 3 fans, an ssd, some led's, and a better cpu cooler will I still be ok?
fans use very little power compared to everything else in the system and the cpu cooler is just an extra 1-2 fans depending on the cooler. you should be fine!
Just be sure that if you have chosen one of those evga psu that have a multi rail design that you run a cable from each rail to the gpu. Apart from that you'll be fine as you're not overclocking. Fans, hdds, lights etc consume bugger all power so nothing to worry about there.