I don't think you can cool both your cpu and gpu for 230. The cheapest way to cool your gpu is to use a universal gpu and add heat sinks to the Vregs and Vram. The universal gpu will run you around 50 plus the heat sink cost. However, you still need to buy extra barbs for the gpu block and more tubing. Likewise, cooling both the cpu and gpu will require a larger rad or more rads, which incur a higher cost to purchase a radiator or radiators. You also need a place to mount the radiator and if your case is too small you need to mount it externally with a external mod kit.
The absolute cheapest way to cool your cpu and gpu is to use a rasa 750 RX360 kit, which cost 189.99, but doesn't include shipping. Once shipping cost factor in your looking at around 200 plus you still need to buy barbs, new tubing, universal gpu block, and heat sinks for vram and vregs plus shipping. Undoubtedly, the kit's weakest items are the tubing, pump, and fans. The fans can perform, but don't give you very good noise to performance compared to gently typhoons or even yate loon fans. The pump isn't as reliable or as silent like ddc or swiftech 655 mainstream pumps. As for the tubing, you need to plan out replace the tubing that comes with the kit. It's not very good.
Going custom allows you to bypass those problems, but will cost more.
Frankly, I don't think it's possible to cool your gpu and cpu for 230 or less using new parts only. If you can find used parts you might make it work. The cheapest cost for adding a gpu came around 260-270 using a rasa rx360 kit and didn't including new tubing, barbs, or shipping. The actually cost is closer to 290-300. Those numbers are vaguely what I remember when I was trying to figure out cost for my water cooling rig, before I got a boost to my budged from $260-$300 to $400-$450. If you decided to water cool your cpu or gpu be aware that some times things don't workout the way you plan and your forced to spend more. This especially true for custom water cooling until you have a lot more experience.
The point I'm making it's a good idea to have some reserve money in case you need to buy some extra items for whatever reason. If you spend all your money and run into a problem you might not be able to finish your water cooling system. It's also takes a lot more time to build your system especially if you plan to cool your gpu too, which require your to remove your gpu stock cooler. I knew it was a lot more work, but you really don't know how much more work until your actually doing the work or how long it would take to set up your wc computer. It's been at least two weeks since I physically started building my water cooling system, but ran into problems so I had to return items or order new parts.
Edited by Bekster - 7/30/12 at 4:16am