General thoughts:
PSU is alright for that system, but won't let you move up to significantly more power-hungry parts in the future.
Keep in mind you can't use all the space in an SSD (or an HDD either for than matter, HDDs need ~15% free to allow auto-defrag). 15% is a good rule of thumb to leave free on an SSD without getting performance problems - a 120GB drive will give you about 95GiB of actual space, Win8 will eat another 20GB, so you're realistically looking at 60-70GB of free space for your stuff.
You don't really need a third-party CPU cooler, biggest difference will be that it runs quieter, (And might let the CPU run better turbo speeds.)
I was mistaken about hybrid crossfire support earlier (as I mentioned in #fiftychat), there probably isn't much point in that cpu if you're running a 5770 card. The Athlon X4 760K is nearly the same processor (100 MHz slower) except without the GPU, and $50 cheaper. For roughly the same price as the 6600K I'd look at either the i3-3240/i3-4130 or FX-4130/FX-4300/FX-4350.
PSU is alright for that system, but won't let you move up to significantly more power-hungry parts in the future.
Keep in mind you can't use all the space in an SSD (or an HDD either for than matter, HDDs need ~15% free to allow auto-defrag). 15% is a good rule of thumb to leave free on an SSD without getting performance problems - a 120GB drive will give you about 95GiB of actual space, Win8 will eat another 20GB, so you're realistically looking at 60-70GB of free space for your stuff.
You don't really need a third-party CPU cooler, biggest difference will be that it runs quieter, (And might let the CPU run better turbo speeds.)
I was mistaken about hybrid crossfire support earlier (as I mentioned in #fiftychat), there probably isn't much point in that cpu if you're running a 5770 card. The Athlon X4 760K is nearly the same processor (100 MHz slower) except without the GPU, and $50 cheaper. For roughly the same price as the 6600K I'd look at either the i3-3240/i3-4130 or FX-4130/FX-4300/FX-4350.