If it's just for fun, go with Swiftech parts, they're well made. The MCP350/355 is an excellent pump and any dual or triple radiator well work with it. I prefer 3/8" tubing over 1/2 for ease of routing, and the flow rate hit is small until you get down to 1/4".
That said, if you're looking for value, avoid water cooling like the plague. I sold off all of my WC parts a few years ago after realizing I spent 5x as much only to get the same cooling a a high end tower heatsink, with more noise. If you're looking for performance, be aware that a stock i5 under the stock Intel cooler will be faster and quieter and cheaper than an FX with watercooling.