Water cooling is directly cooling a device more efficiently. So watercooling has the possibility to cool an individual component better (air has the heat absorption rate very close to wood). It literally takes heat directly off the component, moves it through tubes, where it then gets to deal with the air exchange; however, here it is being kicked directly out of the case while internal heatsinks just pump into the case and why a lot of folks rely on having a lot of fans...they have to.
There's a LOT more perks with watercooling than a perceived longer component life. Less fans, less noise, direct cooling so you can overclock better. I've never heard someone want to water cool to make their CPU last longer. I mean, my Pentium II's still work and they were air cooled. What usually fails is another component and not a CPU/GPU.
So to your question, I also feel you're fine with those mammoth 200mm OEM fans. You still want some air moving in and out to cool the other components that will get less without a local fan you're replacing with a waterblock; but you aren't doing yourself any favors by simply adding more fans (+more noise). Depending on what type of kit or loop you are planning, you really might think about getting the GPU in on the H2O fun. The loudest thing in any of my cases, OC'd, stock, or whatever...is the GPU fan. Sure you can get a program to make your own speed ramps vs. temps, but eventually they're still at full tilt when your doing anything aggressive like your 3D work. IMO, H2O just really tames that beast and gets the case back to being reasonable and gentlemanly.
The best way to do this is usually a DIY 3/8" loop, but there's still some boxed GPU kits; albeit rare. The last kit I knew of 1st hand was CoolIt systems, but they've moved on to designing for others (Corsair and Antec mainly) and don't sell their own stuff anymore. They also have their own rads, so the CPU kit needs room for a 120mm fan and the GPU room for it's own rad too. A DIY kit can be planned with a much better rad that will handle both the CPU and GPU in one heat exchanger. Right now, I have a 3350P and a 560Ti on a 3/8" loop going to an ancient Black Ice Extreme 120mm from way back in 2002 or so; does fine.
Here, cost is the big factor and can easily be into this for about $500 initially vs $250 two kitted loops would cost. To me, it's an investment and can use all the parts over and over again on many builds to come, even decades later such as what I'm using. Just change blocks if needed, this costs just as much as a HS/F does, then you're back running again. It's an initial investment and won't cost very much at all if you chose to reuse parts of the loop in another build. With this 11yo investment, I spent $60 on a DD CPU block and $85 on a full coverage DD GPU block. I couldn't get CLOSE to that price or cooling ability going with air cooling equipment.