Looks like a reasonable plan for a watercooled setup. You'll hear all kinds of wild claims about how effective watercooling is and how low it's pushed the temperatures. Ignore them all - they all have a whiff of fisherman's yarn
Taken from a purely thermodynamic perspective, there are some rules of thumb for minimum temperature differences between air and water, and water and CPU, at equilibrium:
Bare minimum difference between radiator fins and air is 10ºC for a normally-flowing radiator. There's a couple more ºC between the radiator and the water. Realistically expect the water to be 15ºC warmer than the room.
Bare minimum temperature difference between the water and the waterblock, taken at the outlet is about 5ºC. The CPU will thus be 5ºC hotter than a perfectly effective waterblock. The residence time of water in the waterblock is small, so a block-volume of water will not heat up much inside the block, so you can neglect this.
Which brings us to the rough-guide for what CPU temps you should be expecting. About 20ºC warmer than your room. So in a nicely air conditioned office (18ºC), you'd be looking at sub-40ºC temperatures.
I see you've gone for a combined reservoir/radiator setup. I personally don't favour large reservoirs, preferring to actually dissipate waste heat rather than just storing it up for a warmer future. The effect of the reservoir will be to cause your system to take a long time - possibly hours, possibly even days - to reach thermal equilibrium where the above rule holds true. Until that time, you'll see lower temperatures, rising slowly over time. These pre-equilibrium temperatures are what a lot of people report, which is where they get thermodynamically impossible performance out of their cooling loops.
Though he's left active posting, Random Nonsense built a cooling loop with obscenely large radiators that brought the water back to room temperature on each pass. This system WAS able to improve on the approximate guide above.
I expect to see a lot of people posting up results claiming stable CPU temperatures of only 5ºC above room temperature. I'd imagine those computers are powered by a perpetual-motion generator in the back yard.
Watercooling's definitely a fun thing to try - enjoy playing
